Create WifiPermissionChecker in SettingsLib

- Get the launched package name from ActivityManager

- Add method to check ACCESS_WIFI_STATE permission

- Add method to check ACCESS_FINE_LOCATION permission

Bug: 187176859
Test: manual test
make RunSettingsLibRoboTests \
    ROBOTEST_FILTER=WifiPermissionCheckerTest

Change-Id: Ia5de60b88fc97ef532941c0c10ebf069d4216134