[Android] PlaybackService: fix AudioFocus

[Thomas Guillem]

vlc-ports/android | branch: master | Thomas Guillem <thomas at gllm.fr> | Tue Jun 30 16:19:31 2015 +0200| [5dcc351df7debfc13d499b9355af39ef3f8f8f64] | committer: Thomas Guillem

PlaybackService: fix AudioFocus

Handle it only in PlaybackService.

> http://git.videolan.org/gitweb.cgi/vlc-ports/android.git/?a=commit;h=5dcc351df7debfc13d499b9355af39ef3f8f8f64
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 .../src/org/videolan/vlc/PlaybackService.java      |  182 ++++++++++++--------
 .../vlc/gui/video/VideoPlayerActivity.java         |   69 --------
 2 files changed, 108 insertions(+), 143 deletions(-)

Diff:   http://git.videolan.org/gitweb.cgi/vlc-ports/android.git/?a=commitdiff;h=5dcc351df7debfc13d499b9355af39ef3f8f8f64