Fixes crash on recording stop

On video playback resume back from mulittaskiing, connection to
playbackservice could fail and mess video playback

AudioTrack will say it support multi channels but it will just cut every
channels after 2.0. That's why we could not hear the voice with some medias on
some devices (Nexus 6p, Chrome book).

Fixes #800

Fix #805

This can prevent Medialibrary reloading on app startup