Remove @hide from overridden methods

It is unclear whether various methods were marked with @hide because
of issues with compilation, because they registered as an API change
or because the caused problems with doc gen. No obvious problems can
found today so they are being removed here.

Bug: 74379469
Test: make checkbuild / make droid
Change-Id: I97b2774fb77f1361bd6c7f3c13d1cb9c980a3df4