[Unfold Animation] Expose hinge angle provider interface

Exposes hinge angle provider instance from
the dagger component so the clients could
use it to stop/start the hinge angle
provider (which will subscribe/unsubscribe
from the sensor).

Bug: 258828766
Test: presubmit
Change-Id: Ib3f7d41a1ce95f9d3eca4305d16c7e32eb873d04