With the new application workflow and unified player, video detail page and video player are the same activity. So show only one of these options based on whether autoplay is enabled or not, and show both if using external player
For all manually-created images PNG have been kept.
- rename all icon attrs to have a `ic_` prefix
- always use `_24dp` icons, because there is no real difference, since they are vector drawables
- always use the original name found on material.io for icon drawables, as to not create confusion and possibly duplicates. Icon names can still be different from real drawable names, though I have made some of them compliant to this or maybe more meaningul.
- remove duplicate `getIconByAttr()` in ThemeHelper (use `resolveResourceIdFromAttr()`
- use standard icons for `expand_more` and `expand_less` instead of triangles
- use `play_button_outline` instead of custom PNG as play button in VideoDetailFragment (questionable, as there is no shadow anymore)
- main, background, popup players now connected via one service, one view, one fragment, one activity and one gesture listener
- playback position is synchronized between players. Easy to switch from one to another
- expandable player at the bottom of the screen with cool animation and additional features like long click to open channel of a video, play/pause/close buttons and swipe down to dismiss
- in-player integrated buttons for opening in browser, playing with Kodi, sharing a video
- better background playback that can be activated in settings. Allows to automatically switch to audio-only mode when going to background and then switching to video-mode when returning to the app.
* restore permission request popup previously removed in #2486
* use legacy file picker in cases where saf file picker is not available
* fix missing file check logic in prepareSelectedDownload method (DownloadDialog.java)
