Only return one mobile subscription per group in Settings.

Right now getSelectableSubscriptionInfoList returns all subscriptions
that are visible and available. But we should only show one per
subscription group. So updating getSelectableSubscriptionInfoList
to make sure of it.

Bug: 126438122
Test: manual - group Fi primary subscriptions and make sure only
one Fi subscription is shown in Settings UI.
Change-Id: I867296b4f8efbdf2e9885ef34dd45806fa0abbca
1 file changed