RotationHelper: use FoldStateListener to get folded info

displayId isn't updated if device is folded/unfolded with screen off.
Use DeviceStateManager.FoldStateListener to track folded state is able
to get correct state even if screen is off.

Bug: 197196724
Test: manual test

Signed-off-by: Jasmine Cha <chajasmine@google.com>
Change-Id: Ia9c8257e95d06f2daaba99d4deb9cf7590490bcd