Use @SystemApi methods to interact with telephony

As part of the Telephony mainline effort, remove @hide dependencies
on telephony in RCS:
1) Use ImsMmTelManager/ProvisioningManager for querying configs.
2) Expose UCE APIs that are needed so far.
3) Use @SystemApi versions of SubscriptionManager/TelephonyManager APIs
4) In PresencePolling app, track default subscription as active
SIM for capability polling (since it doesnt support MSIM yet).

Bug: 147319232
Test: atest CtsTelephonyTestCases; manuallay add contacts, check publish
Merged-In: Ia9f1e8a94896a11201dbd66344fc1caf0589ffc7
Change-Id: Ia9f1e8a94896a11201dbd66344fc1caf0589ffc7
10 files changed
tree: 975d529c77cfa5b43fadff5919f661c5989c60b9
  1. rcs/
  2. OWNERS