power/stats: Update HIDL to use synchronous FMQ

Unsynchronous queue do not help solve the problem of
supporting multiple clients of power.stats. Since, there
is no current requirement to support multiple clients so
using synchronous queues instead.

BUG: 117424656
BUG: 111185513
Test: run vts -m VtsHalPowerStatsV1_0Target
Change-Id: Iab73de5a460e2a0ec5e949f8b021a87aefed58c8
(cherry picked from commit 84a48b83)
Merged-In: Iab73de5a460e2a0ec5e949f8b021a87aefed58c8