Introduce `PillarboxPreloadManager`

[MGaetan89]

Pull request

Description

This PR introduces a PillarboxPreloadManager and related classes. It also updates the OptimizedStory to use this new helper.

The PillarboxPreloadManager takes the same arguments as DefaultPreloadManager/PillarboxExoPlayer, with the addition of a PlayerPool. This allows PillarboxPreloadManager to create player on-demand, and reuse them if needed.

Changes made

• Introduce a new PillarboxPreloadManager.
• Introduce a new PlayerPool.
• Introduce a new PillarboxPreloadManager.
• Introduce a new PillarboxRenderersFactory.
• Introduce a new PillarboxTrackSelector.
• Update StoryViewModel to use the new PillarboxPreloadManager.
• Update OptimizedStory to scroll vertically instead of horizontally.
• The pager indicator has been moved to the right of the screen instead of the bottom.
• A progress indicator has been added at the bottom of each page.
• Use StringUtil in SimplePlayerViewModel.

[!NOTE] AndroidX Media3 1.5.0 introduces some changes regarding preload manager. In particular, DefaultPreloadManager.Status.STAGE_LOADED_TO_POSITION_MS will become DefaultPreloadManager.Status.STAGE_LOADED_FOR_DURATION_MS, and will take milliseconds instead of microseconds. This can be addressed once AndroidX Media3 1.5.0 is stable.

Checklist

• [x] Your branch has been rebased onto the main branch.
• [x] APIs have been properly documented (if relevant).
• [x] The documentation has been updated (if relevant).
• [x] New unit tests have been written (if relevant).
• [x] The demo has been updated (if relevant).
• [x] All pull request status checks pass.

[github-actions[bot]]

Code Coverage

Overall Project	48.48% -0.42%	🟢
Files changed	62.9%	🟢

Module	Coverage
:pillarbox-player	58.06% -0.19%	🟢
:pillarbox-ui	0.2% -1.49%	🟢

Files

|Module|File|Coverage|| |:-|:-|:-|:-:| |:pillarbox-player|[PillarboxTrackSelector.kt](https://github.com/SRGSSR/pillarbox-android/blob/e9d5c9a1a6a08ae400c00a975718077ec87dd112/pillarbox-player%2Fsrc%2Fmain%2Fjava%2Fch%2Fsrgssr%2Fpillarbox%2Fplayer%2FPillarboxTrackSelector.kt)|100%|🟢| ||[PillarboxBandwidthMeter.kt](https://github.com/SRGSSR/pillarbox-android/blob/e9d5c9a1a6a08ae400c00a975718077ec87dd112/pillarbox-player%2Fsrc%2Fmain%2Fjava%2Fch%2Fsrgssr%2Fpillarbox%2Fplayer%2FPillarboxBandwidthMeter.kt)|100%|🟢| ||[PillarboxRenderersFactory.kt](https://github.com/SRGSSR/pillarbox-android/blob/e9d5c9a1a6a08ae400c00a975718077ec87dd112/pillarbox-player%2Fsrc%2Fmain%2Fjava%2Fch%2Fsrgssr%2Fpillarbox%2Fplayer%2FPillarboxRenderersFactory.kt)|100%|🟢| ||[PillarboxPreloadManager.kt](https://github.com/SRGSSR/pillarbox-android/blob/e9d5c9a1a6a08ae400c00a975718077ec87dd112/pillarbox-player%2Fsrc%2Fmain%2Fjava%2Fch%2Fsrgssr%2Fpillarbox%2Fplayer%2FPillarboxPreloadManager.kt)|86.29% **`-13.71%`**|🟢| ||[PillarboxExoPlayer.kt](https://github.com/SRGSSR/pillarbox-android/blob/e9d5c9a1a6a08ae400c00a975718077ec87dd112/pillarbox-player%2Fsrc%2Fmain%2Fjava%2Fch%2Fsrgssr%2Fpillarbox%2Fplayer%2FPillarboxExoPlayer.kt)|79.3% **`-0.63%`**|🟢| |:pillarbox-ui|[AndroidPlayerSurfaceView.kt](https://github.com/SRGSSR/pillarbox-android/blob/e9d5c9a1a6a08ae400c00a975718077ec87dd112/pillarbox-ui%2Fsrc%2Fmain%2Fjava%2Fch%2Fsrgssr%2Fpillarbox%2Fui%2Fwidget%2Fplayer%2FAndroidPlayerSurfaceView.kt)|0% **`-28.74%`**|🟢|

[MGaetan89]

Looks good to me 👍🏻

@StaehliJ I can't approve it, since I opened the PR. Feel free to approve it, then we can merge it. I just pushed a couple small changes https://github.com/SRGSSR/pillarbox-android/pull/726/commits/1a1a9fe0c198498dbcb27b9f2d3b4c6a87b77f8b

[MGaetan89]

I've switched the runner for the Android Tests step to ubuntu-22.04. See https://github.com/SRGSSR/pillarbox-android/pull/736#issuecomment-2407408319 for more details.

[MGaetan89]

Looks like Google will make it easier to share parameters between the DefaultPreloadManager and ExoPlayer in the next version: https://github.com/androidx/media/commit/98dc7f2def8b7404383a118d02f309870a5bede4

[MGaetan89]

I've reverted my change to the runner. See https://github.com/SRGSSR/pillarbox-android/issues/747#issuecomment-2410190157