Expand nuplayer mutex for mediametrics management

refactor some mutex for how nuplayer sets up mediametrics data.
expanded locking to eliminate a couple race conditions.

Bug: 151644303
Bug: 151643722
Test: poc attached to bugs
Merged-In: I75f29a6254c5eab5d4f524ee7a7ef59f93a0b405
Change-Id: Ia2e68ef616e249a6e8746b9068f22bd208a0ffc8
(cherry picked from commit e5767553f55fb30d9d58ba211ec68e64a6266e52)
diff --git a/media/libmediaplayerservice/nuplayer/NuPlayerDriver.h b/media/libmediaplayerservice/nuplayer/NuPlayerDriver.h
index ad878f8..37c53b0 100644
--- a/media/libmediaplayerservice/nuplayer/NuPlayerDriver.h
+++ b/media/libmediaplayerservice/nuplayer/NuPlayerDriver.h
@@ -142,6 +142,7 @@
     uint32_t mPlayerFlags;
 
     MediaAnalyticsItem *mAnalyticsItem;
+    mutable Mutex mMetricsLock;
     uid_t mClientUid;
 
     bool mAtEOS;