Updates import statement

Signed-off-by: Darshit Chanpura <[email protected]>

src/integrationTest/java/org/opensearch/security/DoNotFailOnForbiddenTests.java

@@ -12,6 +12,7 @@
 import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStreamReader;
+import java.nio.charset.StandardCharsets;
 import java.util.List;
 import java.util.stream.Collectors;