move audio unit initialization after audio session initialization and setup fixes issues when trying to start playback from background
move audio unit initialization after audio session initialization and setup fixes issues when trying to start playback from background

Signed-off-by: Felix Paul Kühne <af44a38b4065def9b90f0b66e4658837dd45b77d@videolan.org>
(cherry picked from commit 1ee464915748e9efb00464d2e926c27e1513a4bd)

jomanmuk/vlc-2.2,jomanmuk/vlc-2.2,jomanmuk/vlc-2.2,jomanmuk/vlc-2.2,jomanmuk/vlc-2.2,jomanmuk/vlc-2.2,jomanmuk/vlc-2.2