Mark PROCESS_OUTGOING_CALLS permission as deprecated.

We deprecated the NEW_OUTGOING_CALL broadcast which uses this, so we
should also deprecate the permission to make it more clear to the
developers.

Test: Build / make api
Bug: 129531123
Bug: 129572090
Change-Id: Iac4979ffe29c33eb2ed8ffe4a7799e7caa794951