Fix build errors: update all callers of changed function signatures

Three callers were missing the new use_ffm parameter:
- aws_signing.c: aws_input_stream_new_from_java_http_request_body_stream()
  -> add false (signing path always uses JNI)
- mqtt_connection.c: aws_apply_java_http_request_changes_to_native_request()
  -> add false (MQTT path always uses JNI)
- mqtt5_client.c: aws_apply_java_http_request_changes_to_native_request()
  -> add false (MQTT5 path always uses JNI)

Also fix the unused-parameter warning in http_request_utils.c:
- aws_apply_java_http_request_changes_to_native_request() now passes
  use_ffm through to aws_input_stream_new_from_java_http_request_body_stream()
  instead of hardcoding false, making the parameter actually used.

Author: sbSteveK

src/native/aws_signing.c

@@ -494,7 +494,7 @@ void JNICALL Java_software_amazon_awssdk_crt_auth_signing_AwsSigner_awsSignerSig
         AWS_FATAL_ASSERT(callback_data->java_original_chunk_body != NULL);
 
         callback_data->chunk_body_stream = aws_input_stream_new_from_java_http_request_body_stream(
-            aws_jni_get_allocator(), env, java_chunk_body_stream);
+            aws_jni_get_allocator(), env, java_chunk_body_stream, false /* use_ffm: signing path uses JNI */);
         if (callback_data->chunk_body_stream == NULL) {
             aws_jni_throw_runtime_exception(env, "Error building chunk body stream");
             goto on_error;

src/native/http_request_utils.c

@@ -435,10 +435,9 @@ int aws_apply_java_http_request_changes_to_native_request(
     }
 
     if (jni_body_stream) {
-        /* use_ffm=false here: this path is used by non-S3 HTTP requests that
-         * don't go through the FFM meta-request path. */
+        /* Pass use_ffm through so the stream uses the correct callback path. */
         struct aws_input_stream *body_stream = aws_input_stream_new_from_java_http_request_body_stream(
-            aws_jni_get_allocator(), env, jni_body_stream, false);
+            aws_jni_get_allocator(), env, jni_body_stream, use_ffm);
 
         aws_http_message_set_body_stream(message, body_stream);
         /* request controls the lifetime of body stream fully */

src/native/mqtt5_client.c

@@ -1650,7 +1650,7 @@ JNIEXPORT void JNICALL Java_software_amazon_awssdk_crt_mqtt5_Mqtt5Client_mqtt5Cl
     }
 
     if (aws_apply_java_http_request_changes_to_native_request(
-            env, jni_marshalled_request, NULL, ws_handshake->http_request)) {
+            env, jni_marshalled_request, NULL, ws_handshake->http_request, false /* use_ffm: MQTT5 path uses JNI */)) {
         error_code = aws_last_error();
         goto done;
     }

src/native/mqtt_connection.c

@@ -1290,7 +1290,7 @@ void JNICALL Java_software_amazon_awssdk_crt_mqtt_MqttClientConnection_mqttClien
     }
 
     if (aws_apply_java_http_request_changes_to_native_request(
-            env, jni_marshalled_request, NULL, ws_handshake->http_request)) {
+            env, jni_marshalled_request, NULL, ws_handshake->http_request, false /* use_ffm: MQTT path uses JNI */)) {
         error_code = aws_last_error();
         goto done;
     }