Fix not smoothly dialog transition in Hearing devices dialog

Root Cause: Dimiss dialog before doing diloag transition

Solution: ActivityTransitionAnimator.Controller will take care of dimissing dialog, we don't need to
manually dismiss it.

Bug: 406484328
Test: atest HearingDevicesDialogDelegateTest
Flag: EXEMPT bugfix
Change-Id: I5f7a547fea06a420881ab17abf1493d68e311711