Add more logging for wakelock stats inquiries

Add additional logging after receiving wakelock statistics from
SystemSuspend via AIDL.

Test: atest FrameworksCoreTests:KernelWakelockReaderTest
Test: manually verified new log presented
Bug: 173539101
Change-Id: Ia64ca7edaa4c7925348e1c31d5681943cfbe4f33