Support tests run by non-system user.

Followed guideline doc https://g3doc.corp.google.com/company/teams/android/teampages/android-rubidium/eng/guides/dev-guide/rb-test-mu.md?cl=head

Test: atest  --user-type secondary_user   FrameworksWifiNonUpdatableApiTests:android.net.wifi.sharedconnectivity.service.SharedConnectivityServiceTest
Flag: EXEMPT test
Fixes: 396862192

Change-Id: Ie951a51f2f95049713796ae23b1077157cddfeba