Add new flag for "robust number verification".

Also added a test case for number normalization to verify it can handle the
particular case we're interested in.

Test: Added new unit tests to cover matching of these numbers.
Test: Manual testing using shell command to confirm correct behavior of
the API from an end-to-end standpoint.
Test: Via test app and shell override.
Flag: com.android.internal.telephony.flags.robust_number_verification
Fixes: 400984263

Change-Id: I8bef2480af3a9bb0337eb5a1bdc08cf39bc06a9d