Add metrics for region change dialog

1. ACTION_CHANGE_REGION_DIALOG_POSITIVE_BTN_CLICKED
2. ACTION_CHANGE_PREFERRED_LANGUAGE_REGION_POSITIVE_BTN_CLICKED
3. ACTION_CHANGE_REGION_DIALOG_NEGATIVE_BTN_CLICKED
4. ACTION_CHANGE_PREFERRED_LANGUAGE_REGION_NEGATIVE_BTN_CLICKED

Bug: 389568296
Test: manual
Flag: EXEMPT bugfix
Change-Id: Ic6739c8ec31f8027d6879b584cd92a748d5c7f12