Android VLC player sometimes plays .m4a audio files as black videos with .m4a tracks.

= VLC app version=	2.0.6
= VLC Build=	Revision !30 (merged)ebb0d VLC: !b4b26b9 (2016-08-12) ARMv8
This version of VLC is compiled by: jb@vin (2016-08-12)
I have a music collection of _m4a_s. I can reproducibly cause the Android VLC app to play some of my m4a-files as a black video instead of an audio file. This is especially irritating as it will cause the app to un-background itself and interrupt my current task.

I checked the verbosity check box and captured ~20 seconds of logs. I first play one track and then stop it and immediately play the other track. Both tracks are different versions of the same song, with different album art (I use tools to find and embed album art and tags in the music). One track will play correctly as an audio file, the other track will incorrectly attempt to play video (even when I'm trying to play it from the "Audio" tab of the app.

Specs

= Hardware=	Motorola Droid 2 Turbo Phone
= Android version=	6.0.1
= Kernel version=	3.10.84-perf-gabde09e hudsoncm@ilclbld29 [#1](https://code.videolan.org/videolan/vlc/-/issues/1) Sat Sep 17 10:08:38 CDT 2016
= System version=	4.31.22.kinzie_verizon.en.US
= Build number=	MCK24.183-22