Fix issue 5462427: Volume should never be 0 ...
Fix issue 5462427: Volume should never be 0 ...

Make sure that ring or notification volume index
never reaches 0 unless in silent mode.
Conversely, enter silent mode when this volume is set to 0.

Change-Id: Iff5e5e972b607f4736e7a704b26b2dadb40074b0

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