Freeze android.hardware.power.stats

This was done in ag/22462586 internally which is too large to
cherry-pick. It's being applied to aosp to unblock some trunk stable
work.

This CL is generated with:
`m android.hardware.power.stats-freeze-api`

Test: m
Bug: 290265210
Change-Id: I385860dbd7e0d183e159353b2e2d0f8fb5b444eb
Merged-In: I832ab7a8b5445ba85e27bbcf5be64906bfa0e5be