Fix: Bluetooth and Wifi scanning location MainSwitch page policy transparency.

When DISALLOW_CONFIG_LOCATION is set, make location service's
MainSwitchPreference pages for wifi scanning and bluetooth scanning
unavailable too, so that intent direct access is disabled.

screenshot: http://shortn/_kkK3BMTSh1

Bug: 277333746
Bug: 277333781
Test: atest SettingsRoboTests, on device
Change-Id: I52f9a11b1dd78a5e5dbb1bbde3cda7381c87ae39