DO NOT MERGE Selectively show volume UI on first volume change event.

Only show volume dialog on first volume change event if the flags
related to the event are set to show UI.

For example, this allows us to not show the volume dialog if the volume
is changed from sound settings as the first volume change event.

Bug: 145134692
Bug: 145094923
Test: Manual
Change-Id: I9bf7eeb009a792e7205265add2cc6b1b0d542168