Update to ConnectivityService to use utils

Update to ConnectivityService to use permission utils to validate the
existence of a system feature.

Bug: 210485380
Test: atest FrameworksNetTests:
com.android.server.ConnectivityServiceTest

Change-Id: Ia537cc5b37ef8d80f49f1a83ba572b3b8a9f6874
1 file changed