Fix bypass CALL_PRIVILEGED permission in AppRestrictionsFragment

In onReceive of AppRestrictionsFragment.java, there is a possible way to
start a phone call without permissions due to a confused deputy.
This could lead to local escalation of privilege with no additional
execution privileges needed.

We should not allow the restrictionsIntent to startActivity simply
because it resolves to multiple activities.
Instead, we should call resolveActivity and check the result's package
name is same as current package name, then it is safe to startActivity.

Bug: 200688991
Test: manual verify
Change-Id: Iaa2d3a9497c3266babe0789961befc9776a4db7a