Add pushing many batterystats events to statsd

Statsd is now informed for starts/stops/etc of the following events:
BleScan
BleScanUnoptimized
BleScanResult
Sensor
Gps
Sync
ScheduledJob
UidWakelock (aggregate wakelock)
LongPartialWakelock
BatterySaverMode (power save mode)
DeviceIdleMode (doze)
ScreenBrightness
Audio
Video (media codec)
Camera
Flashlight
ProcessLifeCycle

TODO: Note that, although tags are java constants (e.g.
StatsLog.SCREEN_STATE), the values passed in for states do not have java
constants associated with them, so we use literals (0 vs 1 for off vs
on). In the future, when corresponding java constants exist, these can
be updated.

Test: manually confirmed statslog received each type of events
Change-Id: I24282cdb56265bba61dceb0932112804273dcfc8