Make DefaultNettyConnection backward compatible

Motivation:

#2079 added a new argument for 2 public methods of
`io.servicetalk.transport.netty.internal.DefaultNettyConnection`.
While this is an internal class, we should be extra cautious with any
incompatible changes in 0.41 branch.

Modifications:

- Add 2 more overloads for pre-existing methods and mark them as
`@Deprecated`;

Result:

`servicetalk-transport-netty-internal` module is backward compatible
with 0.41.13.

servicetalk-transport-netty-internal/src/main/java/io/servicetalk/transport/netty/internal/DefaultNettyConnection.java

@@ -214,6 +214,44 @@ private DefaultNettyConnection(Channel channel, BufferAllocator allocator, Execu
         this.enrichProtocolError = requireNonNull(enrichProtocolError);
     }
 
+    /**
+     * Given a {@link Channel} this will initialize the {@link ChannelPipeline} just to create a
+     * {@link DefaultNettyConnection}. It is assumed this is a child channel and all TLS handshaking is completed.
+     * @param channel A newly created {@link Channel}.
+     * @param allocator The {@link BufferAllocator} to use for the {@link DefaultNettyConnection}.
+     * @param executor The {@link Executor} to use for the {@link DefaultNettyConnection}.
+     * @param terminalPredicate Used to determine which inbound signal on the {@link #read()} stream terminates the
+     * current message framing and will allow a resubscribe to consume the next framing.
+     * @param closeHandler Manages the half closure of the {@link DefaultNettyConnection}.
+     * @param flushStrategy Manages flushing of data for the {@link DefaultNettyConnection}.
+     * @param idleTimeoutMs Value for {@link ServiceTalkSocketOptions#IDLE_TIMEOUT IDLE_TIMEOUT} socket option.
+     * @param executionStrategy Used to derive the {@link #executionContext()}.
+     * @param protocol {@link Protocol} for the returned {@link DefaultNettyConnection}.
+     * @param sslSession Provides access to the {@link SSLSession} associated with this connection.
+     * @param parentChannelConfig {@link ChannelConfig} of the parent {@link Channel} to query {@link SocketOption}s.
+     * @param streamObserver {@link StreamObserver} to report internal events.
+     * @param isClient tells if this {@link Channel} is for the client.
+     * @param enrichProtocolError enriches protocol-specific {@link Throwable}s.
+     * @param <Read> Type of objects read from the {@link NettyConnection}.
+     * @param <Write> Type of objects written to the {@link NettyConnection}.
+     * @return A {@link Single} that completes with a {@link DefaultNettyConnection} after the channel is activated and
+     * ready to use.
+     * @deprecated Use {@code #initChildChannel(Channel, BufferAllocator, Executor, Predicate, CloseHandler,
+     * FlushStrategy, Long, ExecutionStrategy, Protocol, SSLSession, ChannelConfig, StreamObserver, boolean, Predicate,
+     * UnaryOperator)}.
+     */
+    @Deprecated
+    public static <Read, Write> DefaultNettyConnection<Read, Write> initChildChannel(
+            Channel channel, BufferAllocator allocator, Executor executor, Predicate<Read> terminalPredicate,
+            CloseHandler closeHandler, FlushStrategy flushStrategy, @Nullable Long idleTimeoutMs,
+            ExecutionStrategy executionStrategy, Protocol protocol, @Nullable SSLSession sslSession,
+            @Nullable ChannelConfig parentChannelConfig, StreamObserver streamObserver, boolean isClient,
+            UnaryOperator<Throwable> enrichProtocolError) {
+        return initChildChannel(channel, allocator, executor, terminalPredicate, closeHandler, flushStrategy,
+                idleTimeoutMs, executionStrategy, protocol, sslSession, parentChannelConfig, streamObserver, isClient,
+                __ -> false, enrichProtocolError);
+    }
+
     /**
      * Given a {@link Channel} this will initialize the {@link ChannelPipeline} just to create a
      * {@link DefaultNettyConnection}. It is assumed this is a child channel and all TLS handshaking is completed.
@@ -253,6 +291,40 @@ public static <Read, Write> DefaultNettyConnection<Read, Write> initChildChannel
         return connection;
     }
 
+    /**
+     * Given a {@link Channel} this will initialize the {@link ChannelPipeline} and create a
+     * {@link DefaultNettyConnection}. The resulting single will complete after the TLS handshake has completed
+     * (if applicable) or otherwise after the channel is active and ready to use.
+     * @param channel A newly created {@link Channel}.
+     * @param allocator The {@link BufferAllocator} to use for the {@link DefaultNettyConnection}.
+     * @param executor The {@link Executor} to use for the {@link DefaultNettyConnection}.
+     * @param terminalPredicate Used to determine which inbound signal on the {@link #read()} stream terminates the
+     * current message framing and will allow a resubscribe to consume the next framing.
+     * @param closeHandler Manages the half closure of the {@link DefaultNettyConnection}.
+     * @param flushStrategy Manages flushing of data for the {@link DefaultNettyConnection}.
+     * @param idleTimeoutMs Value for {@link ServiceTalkSocketOptions#IDLE_TIMEOUT IDLE_TIMEOUT} socket option.
+     * @param initializer Synchronously initializes the pipeline upon subscribe.
+     * @param executionStrategy {@link ExecutionStrategy} to use for this connection.
+     * @param protocol {@link Protocol} for the returned {@link DefaultNettyConnection}.
+     * @param observer {@link ConnectionObserver} to report network events.
+     * @param isClient tells if this {@link Channel} is for the client.
+     * @param <Read> Type of objects read from the {@link NettyConnection}.
+     * @param <Write> Type of objects written to the {@link NettyConnection}.
+     * @return A {@link Single} that completes with a {@link DefaultNettyConnection} after the channel is activated and
+     * ready to use.
+     * @deprecated Use {@code #initChannel(Channel, BufferAllocator, Executor, Predicate, CloseHandler, FlushStrategy,
+     * Long, ChannelInitializer, ExecutionStrategy, Protocol, ConnectionObserver, boolean, Predicate)}.
+     */
+    @Deprecated
+    public static <Read, Write> Single<DefaultNettyConnection<Read, Write>> initChannel(
+            Channel channel, BufferAllocator allocator, Executor executor, Predicate<Read> terminalPredicate,
+            CloseHandler closeHandler, FlushStrategy flushStrategy, @Nullable Long idleTimeoutMs,
+            ChannelInitializer initializer, ExecutionStrategy executionStrategy, Protocol protocol,
+            ConnectionObserver observer, boolean isClient) {
+        return initChannel(channel, allocator, executor, terminalPredicate, closeHandler, flushStrategy, idleTimeoutMs,
+                initializer, executionStrategy, protocol, observer, isClient, __ -> false);
+    }
+
     /**
      * Given a {@link Channel} this will initialize the {@link ChannelPipeline} and create a
      * {@link DefaultNettyConnection}. The resulting single will complete after the TLS handshake has completed