Add concept of shuffled order to the Player interface (to allow setting and predicting this order when making changes)

Media3 Version

Media3 1.0.0

Devices that reproduce the issue

All

Devices that do not reproduce the issue

--

Reproducible in the demo app?

Yes

Reproduction steps

In https://github.com/androidx/media/issues/273#issuecomment-1472952138 Marc suggested to use controller?.currentTimeline?.getFirstWindowIndex() to get the windowIndex where playback should start.

Unfortunately, the underlying shuffledWindowIndices will be in regular sequential order after adding new items, and are only later being shuffled in ExoPlayerImpl.java#L2266.

This means that after enabling shufflePlayback and adding new items it is currently impossible to directly seek to the first item in the shuffled list (without resorting to some hack and waiting until the order is shuffled)

Expected result

Actual result

Media

Bug Report

• You will email the zip file produced by adb bugreport to dev.exoplayer@gmail.com after filing this issue.