GitLab

Use AudioPlayback_Parameters more consistently in parameter list of
constructors.  Also, StreamPlayer::StreamPlayer was over-assigning to
mPlaybackParams (already assigned by its superclass's constructor).

Move initialization of AudioPlayback_Parameters from each case
to before the switch, as it is shared by each use case.

Remove old asserts.

Change-Id: I8925d36da031c80308457c7e940418d3a4e47b62