visualizer: reset buffer if playback is idle
visualizer: reset buffer if playback is idle

Visualizer capture buffer must be reset if audio framework has stopped
calling process for a given period of time to get read of residual
data from previous captures.

Issue 5571920.

Change-Id: I6e73f971bb812cdbb2979a3b5e763abab07634eb

xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base