Add case to check auto-granting multiple permissions in one group

This change also refactors the assert functions so that they don't have
explicit use of PERMISSION_NAME so these methods can be easily used with other
permissions.

Fixes: 134416270
Test: atest com.android.cts.devicepolicy.MixedManagedProfileOwnerTest#testAutoGrantMultiplePermissionsInGroup
Change-Id: Ib7dc246a2956411fdb4d419b493e0ec2a8394b3b
3 files changed