Add new unknown call apis in ECM, add InCallService to track

Adds new APIs that let certain apps query if there is a call with an
unkown user (read: not a contact) ongoing. Also merges an InCallService
which tracks and updates this state

Bug: 364535720
Test: atest EnhancedConfirmationInCallTest
Flag: android.permission.flags.enhanced_confirmation_in_call_apis_enabled
Relnote: 25Q2 release
LOW_COVERAGE_REASON=FLAG_NOT_ENABLED
Change-Id: I2e260bd911a65f99dd7e7b7b4012b04ef7b51203
12 files changed