libstagefirght: Fix for data loss in A2DP playback with repeat mode

- Data loss is observed in A2DP at the starting of
  second playback with current song repeat mode
-When the file EOS reaches Awesomeplayer calls seek to zero and
 pause the LPAplayer till A2DP thread sent all the data to A2DP.
 Since decoderThread not aware that LPAPlayer in pause state it
 keeps on calling fill buffer.But A2DPThread will be blocked till
 LPAplayer resumes from pause.So buffers which fillbuffer returned
 in pause state are not sent to A2DP and these buffer will be
 over written.
-Added the condition to avoid fillbuffer in decoderThread when
 the LPAplayer is in pause state.

CRs-fixed: 351079
(cherry picked from commit b2ecd5f5b39e3fbee3f73f533897b0d14624244a)

Change-Id: Ib424a5f5794f91df4cad4fbbd7ab27faffcc4ba2