Revert "NuPlayer: use kWhatPauseOnBufferingStart instead of kWhatBufferingStart in RTSPSource."

This reverts commit 2c9a30a341e50f53039e1b7da96dfa91104fdd62.
RTSPSource::pause() will stop receiving data in RTSPSource. This is different from GenericSource::pause().

Change-Id: I2df2bf350731ce0fb1f278942b23ccc6f4f37fb9
diff --git a/media/libmediaplayerservice/nuplayer/NuPlayer.cpp b/media/libmediaplayerservice/nuplayer/NuPlayer.cpp
index cede584..5c13633 100644
--- a/media/libmediaplayerservice/nuplayer/NuPlayer.cpp
+++ b/media/libmediaplayerservice/nuplayer/NuPlayer.cpp
@@ -2142,7 +2142,11 @@
                 mPausedForBuffering = true;
                 onPause();
             }
+            // fall-thru
+        }
 
+        case Source::kWhatBufferingStart:
+        {
             notifyListener(MEDIA_INFO, MEDIA_INFO_BUFFERING_START, 0);
             break;
         }
@@ -2160,7 +2164,11 @@
                     onResume();
                 }
             }
+            // fall-thru
+        }
 
+        case Source::kWhatBufferingEnd:
+        {
             notifyListener(MEDIA_INFO, MEDIA_INFO_BUFFERING_END, 0);
             break;
         }