No longer show disambig when calling SmsManager#getSubId

SmsManager#getSubId used to show a disambig dialog to
pick a default SMS subscription when
SmsManager#getSubscriptionId was called. Since it was used
internally as well, it would cause many of these dialogs
to pop up over and over again.

Do not display the dialog anymore and instead move the
dialog pop up to the methods that actually require the use
of the dialog, such as sending a text.

Bug: 130853716
Test: Manual, Default SMS app
Merged-In: Ibbc07c961f1bdc19e1015885487e9f7b6a14fa83
Change-Id: I71ad38f76750c750b149e4cdcb6fcf99ed89212e