Fix lint errors

WorkSource.WorkChain has setters without getters. We need to read
from the data structure to properly instrument our code for field
metric. We are already violating @VisibleForTesting in BatteryStatsImpl.java
and the autogenerated FrameworkStatsLog.java

Bug: none
Flag: EXEMPT fix lint errors
Test: none
Change-Id: I5ecd5918eff9442ee837c5eafc183bbf1c3074d4