better playback time tracking in nuplayer

Fixes problem where playback time was being cleared as part of
a reset before media.metrics stats were logged.
Added code so that getMetrics() calls will return proper in-progress
playback time (previously, playback time was added to the metrics data
only at the end).
Added initialization of timestamp tracking pauses for rebuffering.

Bug: 74008613
Test: dumpsys media.metrics observation
diff --git a/media/libmediaplayerservice/nuplayer/NuPlayer.h b/media/libmediaplayerservice/nuplayer/NuPlayer.h
index fda69e8..9481234 100644
--- a/media/libmediaplayerservice/nuplayer/NuPlayer.h
+++ b/media/libmediaplayerservice/nuplayer/NuPlayer.h
@@ -99,6 +99,8 @@
 
     const char *getDataSourceType();
 
+    void updateInternalTimers();
+
 protected:
     virtual ~NuPlayer();
 
@@ -180,12 +182,12 @@
 
     Mutex mPlayingTimeLock;
     int64_t mLastStartedPlayingTimeNs;
-    void stopPlaybackTimer(const char *where);
+    void updatePlaybackTimer(bool stopping, const char *where);
     void startPlaybackTimer(const char *where);
 
     int64_t mLastStartedRebufferingTimeNs;
     void startRebufferingTimer();
-    void stopRebufferingTimer(bool exitingPlayback);
+    void updateRebufferingTimer(bool stopping, bool exitingPlayback);
 
     int64_t mPreviousSeekTimeUs;