Fix issue where DownloadedPlayerActivity interferes with MainActivity

[Luna712]

Fixes #605

[Luna712]

This might not be the best way to do this, but it works. If there is a better way, then I apologize this can be closed and that can be tried.

[LagradOst]

bro, I honestly don't see how this fixes the problem, but yet it does??????

[Luna712]

bro, I honestly don't see how this fixes the problem, but yet it does??????

@LagradOst

I updated this for a more efficient solution (seemingly), I realized there was an issue where if you opened download activity then main activity, it tried opening the MainActivity in a PiP window then crashes, this separates the tasks more efficiently now (from testing anyway).

[Luna712]

Basically before, I was wrong, it didn't fix the issue, just reversed its behavior, before it used the most recent opened activity then the first activity failed to respond, the original fix made it crash if say DownloadedPlayerActivity is open in PiP then you try opening MainActivity, it tries opening MainActivity in DownloadedPlayerActivity loading the main application, then crashing because it tries to load an activity already running. The new way, makes DownloadedPlayerActivity use launchMode of singleTask and a taskAffinity for the task ID to prevent conflicts, then ensures the application activity instance is changed when activity is resumed to support both activities running at the same time.

[Luna712]

Thanks for merging, this does make the DownloadedPlayerActivity a lot more proper implementation now, allowing it to be split into a second window altogether so you can say play something from file manager, pause it, go to main CloudStream, and return to the paused window later on without having to replay it. It's when reason I went with that approach and it solved one of the most annoying bugs in the app to me, with this now done, and preview seekbar implemented, I finally was able to make CloudStream the default media player on my phone. Thanks for all your hard work with the app as well!