Test if any broken test to change TestStream coder context.

Author: shunping

sdks/java/core/src/main/java/org/apache/beam/sdk/util/construction/TestStreamTranslation.java

@@ -123,7 +123,8 @@ static <T> RunnerApi.TestStreamPayload.Event eventToProto(
                   .setTimestamp(element.getTimestamp().getMillis())
                   .setEncodedElement(
                       ByteString.copyFrom(
-                          CoderUtils.encodeToByteArray(coder, element.getValue()))));
+                          CoderUtils.encodeToByteArray(
+                            coder, element.getValue(), Coder.Context.NESTED))));
         }
         return RunnerApi.TestStreamPayload.Event.newBuilder().setElementEvent(builder).build();
       default:
@@ -149,7 +150,8 @@ static <T> TestStream.Event<T> eventFromProto(
             protoEvent.getElementEvent().getElementsList()) {
           decodedElements.add(
               TimestampedValue.of(
-                  CoderUtils.decodeFromByteArray(coder, element.getEncodedElement().toByteArray()),
+                  CoderUtils.decodeFromByteArray(
+                    coder, element.getEncodedElement().toByteArray(), Coder.Context.NESTED),
                   new Instant(element.getTimestamp())));
         }
         return TestStream.ElementEvent.add(decodedElements);