Telephony Test: Merge SignalStrengthFacade to PhoneStateListeners.

1. Merge SignalStrengthFacade to PhoneStateListeners.
2. Change the API name to use telephony prefix.
3. Remove the APIs to return individual elements.

BUG: 26337192
Change-Id: I01687abff9d39e5648bebc181fb20b2a32c0eebb
6 files changed
tree: edc1523424c3384d7752e294dc93f10d01d12438
  1. sl4a/
  2. sl4n/