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/media/libmediatranscoding/tests/Android.bp b/media/libmediatranscoding/tests/Android.bp
index 06b9b17..603611a 100644
--- a/media/libmediatranscoding/tests/Android.bp
+++ b/media/libmediatranscoding/tests/Android.bp
@@ -72,3 +72,15 @@
 
     srcs: ["AdjustableMaxPriorityQueue_tests.cpp"],
 }
+
+//
+// TranscodingLogger unit test
+//
+cc_test {
+    name: "TranscodingLogger_tests",
+    defaults: ["libmediatranscoding_test_defaults"],
+    shared_libs: ["libmediandk", "libstatssocket#30"],
+    static_libs: ["libmediatranscoder", "libstatslog_media"],
+
+    srcs: ["TranscodingLogger_tests.cpp"],
+}