MPVActivity: Fix incorrect pause button in certain cases
MPVActivity: Fix incorrect pause button in certain cases

Playback restart does not imply that it's unpaused.
Buggy case: Pausing an audio file and dragging the seekbar to the end

mpv-android/mpv-android,jeeb/mpv-android,mpv-android/mpv-android,mpv-android/mpv-android,mpv-android/mpv-android,jeeb/mpv-android,mpv-android/mpv-android,jeeb/mpv-android,jeeb/mpv-android,jeeb/mpv-android