Note BATTERY_LEVEL_CHANGED semantics.

Despite the name, BATTERY_LEVEL_CHANGED is also sent when the plug type
changes. Note that in the documentation and remove the wtf when that
happens.

Bug: 232840504
Test: N/A
Change-Id: Ib3e0f6c43ecbd5bf1841081b36f4b3eaa8b20039
2 files changed