Cleanup of Cellular/Wifi aggregate statistics

Cleanup of Cellular/Wifi aggregate statistics in Batterystats dumpsys

Cellular
- Modification of field names to improve clarity
- Removed count "x" values
- Added power values to Rx signal strength
- Added power values to Tx power
- Added "Cellular Sleep time"
- Removed erroneous battery field (This is being fixed in b/67213886,
b/67213967)
- Removed the following fields (Mobile radio active unknown time, Mobile
radio active adjusted time, Signal scanning time)

Wifi
- Modification of field names to improve clarity
- Removed count "x" values
- Added power values to Rx signal strength
- Removed the following field (Wifi on, Wifi running)

BUG:67322291
Change-Id: I9630f154a73c7e3cb4bae4779609302f3674602f