Refactor validation before data switch

refactor the validation before data switch flow to be subId generic
instead of specific to opportunistic subId.

Bug: 244064524
Test: existing cts+atest, manual data during phone call
Merged-In: I0cbfaa195d42140426bea533fe83f1d73ac806e2
Change-Id: I0cbfaa195d42140426bea533fe83f1d73ac806e2
3 files changed