Convert PlayerHolder to Singleton; cleanup in VideoDetailFragment; Player/MainPlayer do not call onDestroy() directly#6566

TobiGr merged 5 commits intoTeamNewPipe:devTeamNewPipe/NewPipe:devfrom

bravepipeproject:various-fixes-for-upstreambravepipeproject/BravePipe:various-fixes-for-upstreamCopy head branch name to clipboard