Transcoding: Log transcoder level metrics.

- Add transcoder-level metric logging through west world,
to monitor performance and failures.

- Add new unit tests for TranscodingLogger class.

Bug: 179274112
Test: New and existing unit tests.
Change-Id: Ie8d9bc589c714a7b8be8f4f298c4fa75a81a6e56
diff --git a/services/mediatranscoding/SimulatedTranscoder.h b/services/mediatranscoding/SimulatedTranscoder.h
index 010f0f0..6990576 100644
--- a/services/mediatranscoding/SimulatedTranscoder.h
+++ b/services/mediatranscoding/SimulatedTranscoder.h
@@ -55,11 +55,11 @@
 
     // TranscoderInterface
     void start(ClientIdType clientId, SessionIdType sessionId,
-               const TranscodingRequestParcel& request,
+               const TranscodingRequestParcel& request, uid_t callingUid,
                const std::shared_ptr<ITranscodingClientCallback>& clientCallback) override;
     void pause(ClientIdType clientId, SessionIdType sessionId) override;
     void resume(ClientIdType clientId, SessionIdType sessionId,
-                const TranscodingRequestParcel& request,
+                const TranscodingRequestParcel& request, uid_t callingUid,
                 const std::shared_ptr<ITranscodingClientCallback>& clientCallback) override;
     void stop(ClientIdType clientId, SessionIdType sessionId, bool abandon = false) override;
     // ~TranscoderInterface