Set the type of getInjectedData to {?}.

Reasons:
1) It isn't statically verifiable. Even if you cast the result, it may not be true, as the injected data may change depending on server setup. Thus, you aren't protected from runtime errors so this isn't valuable for type checking.

2) It's not an API we can easily fix. We had to do cr/202516164 to fix local, but there are tons of users of this API.

RELNOTES:n/a

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=203045476

closure/goog/soy/renderer.js

@@ -314,7 +314,7 @@ goog.soy.Renderer.prototype.handleRender = goog.nullFunction;
 /**
  * Creates the injectedParams map if necessary and calls the configuration
  * service to prepopulate it.
- * @return {Object} The injected params.
+ * @return {?} The injected params.
  * @private
  */
 goog.soy.Renderer.prototype.getInjectedData_ = function() {
@@ -335,6 +335,6 @@ goog.soy.InjectedDataSupplier = function() {};
  * `goog.soy.Renderer` will treat the returned data as
  * immutable.  The renderer will call this every time one of its
  * {@code render*} methods is called.
- * @return {Object} A key-value pair representing the injected data.
+ * @return {?} A key-value pair representing the injected data.
  */
 goog.soy.InjectedDataSupplier.prototype.getData = function() {};