Change security model for TelecomManager#handleCallIntent method.

Method is used to trampoline call intents to Telecom. Previously the
calling UID was compared to grant access; this assumption was incorrect
as it wouldn't work for work profiles.

Changed to use a telecom-only permission.

Test: Ran Telecom CTS tests and impacted CTS tests.
Test: Manually placed calls using ACTION_CALL intent.
Bug: 117898288
Change-Id: If7097595e901a418ee90f0a1f1b82dc475838425