power/stats: Add default implementation

Add default implementation for power.stats HAL

BUG: 118777168
BUG: 111185513

Test: run vts -m VtsHalPowerStatsV1_0Target
Change-Id: Id81291f58a5cdfa0cc1f56356001b2862df0dbc2
(cherry picked from commit f94dda77a1e064f2c66d3bd185feda96a9bdcc1e)
Merged-In: Id81291f58a5cdfa0cc1f56356001b2862df0dbc2
5 files changed