WifiServiceImpl: Add new API for scan throttle toggle

We still use the Settings.Global value to persist state, will change
that in a later CL. But, this allows us to stop using the settings value
change as an API.

Bug: 148514485
Test: atest com.android.server.wifi
Test: Verified wifi scan throttle toggle in Developer options
Change-Id: Ie38c56c8056a811ae655942547658fb05f4ee06b
5 files changed
tree: 03d9888bfcb7b6f54a4ef760a27b3c77093a241f
  1. apex/
  2. service/
  3. PREUPLOAD.cfg