NuPlayer: cancel pauseTimeout when tearing down offload

-Issue is when MO call is initiated during offload playback,
 audio is not resuming after disconnecting the call. Reason is,
 when call is started, audio will pause and pauseTimeOut will
 start for offload session. Meanwhile set_mode will invalidate
 all streams, which will send TEAR_DOWN event and restart audio
 with deep buffer mode. But pauseTimeout is not canceled. Since
 source is paused, empty buffers will not be sent to decoder
 during call, this is leading to pause timed out and tear down
 audio again. When call is disconnected, music will not resume
 because, nuplayer is in tearing down state.

-Fix is to call cancelPauseTimeOut when offload session is paused
 and the session is tearing down.

CRs-Fixed: 1049259

Change-Id: I2ddb802647453c6349bf30397f702e72776b649f