(eSim) Return proper portindex for ONS profile.

Better UX handling for carrier selection dialog if
devices under CBRS mode.
ONS profiles are invisible to user hence port index
needs to used for seamless switch scenarios.

Bug: 231347082
Test: manual, atest FrameworksTelephonyTests and all basic eSIM scenarios tested.
Change-Id: I76baf7d7548ea3290de7deee83145babfbb1a478