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
3 files changed