Add carrier config for cross sim calling on opportunistic data.

Flag specifying whether cross sim calling on opportunistic data is supported for carrier.
 - When {@code false} the carrier does not support cross sim calling on opportunistic data.
 - When {@code true} the carrier does support cross sim calling on opportunistic data.

Bug: 199121448
Test: Build.
Change-Id: I2c64949907a861f42f5bd67d445a10de420cd33d