Reconfigure how alarms are setup.

Fixes bug:3368780 Canceling in the Middle of Adding an Alarm Flow is Confusing on Tablet

now:
On existing alarm: can delete, cancel, save(ok)
on new alarm: can cancel or save(ok)
time picker is in the first dialog

Change-Id: I3fa86fc8de4b73ee422e78790a796bad14e404e7