Extract FoldableDeviceStateProvider to a library

Moves FoldableDeviceStateProvider to a separate
java library, so it could shared between
physical devices and cuttlefish devices.
Also makes it public (moves to AOSP).
No changes are made to the functionality,
this is just a move.

Bug: 284266229
Test: manual compile and check on a physical device
Test: presubmit
Flag: none
Change-Id: Ie7f7d334a4904bfbb19baa5dc814291828a8c9eb