Fix crash caused by opening dialogs with a dead activity

This CL fixes crashes that are caused by opening the
PhoneDisambiguationDialogFragment after the associated activity is destroyed.
This is done by detecting when the activity is destroyed or finished.

Bug: 69133504
Test: PhoneNumberInteractionTest
PiperOrigin-RevId: 175623483
Change-Id: Ic639e9e9421205edcb5438d594bb144c6b09dd86