Add AIDL methods to override carrier package

This change introduces a Carrier Service Package override, ensuring that
CTS can export a CarrierService, and set itself as the carrier service.

The requirement for the application to also be carrier-privileged still
stands, but omits the SIM-certificate-match requirement, instead
allowing carrierConfig based certificates + carrier service package
override as a sufficient gate (which critically need to both be doable
with the CTS Shell permission identity)

Bug: 266904760
Test: Manually tested with a demo CTS build, will be used for Core
      Networking CTS tests
Change-Id: I9c31e19dd122123e8e102c901efaa99b2c729635
Merged-In: I9c31e19dd122123e8e102c901efaa99b2c729635
(cherry picked from commit 7e6571f1)