WifiConnectivityManger: Enable background/ePNO scan

Add a new flag to control both background scans & connected PNO scan in
WifiConnectivityManager (We may need to disable connected PNO even if we
enable gscan).
Also, change the disconnected PNO interval to 20 seconds.

BUG: 28020168
BUG: 27877781
Change-Id: I6e7224b02456573070a68dbe8f5a5b0d49f37fdc
2 files changed
tree: f83944350ea9815b0716d656a89bdd2188cc6ff4
  1. service/
  2. tests/