Dialpad redesign.

TESTED:
- Launch Phone UI (previous tab: dialer)
-- Fake menu items should be available
-- Bottom half of the dial button should be clickable
- Launch Phone UI (previous tab: calllog, phone favorite)
-- Real ActionBar should be visible
- Swipe around three tabs.
-- ActionBar (and real menu buttons at the bottom) should be
   visible except when dialer screen is settled down in the
   screen. During horizontal swipes, ActionBar should look
   persistent.
- Click three tabs at the top of screen
-- exactly same as "swipe around three tabs" case above.
- Go to search, and go back from the search (from three tabs)
-- ActionBar should appear/disappear appropriately.

AND, try the sequence above during a phone call, which will
expose DialpadChooser.

- With DialpadChooser, fake buttons should not appear; they should
  appear when the user explicitly choose "add call" item.

KNOWN ISSUE:
- Do horizontal swipe from CallLog to Dialpad. Before the screen
  settling down itself, start swipe from Dialpad to CallLog again.
-- Bottom ActionBar disappears during the migration (which is
   unexpected), because there's no way for the app to determine
   if the user is dragging the screen. The app wrongly detects
   the case as ViewPager.SCROLL_STATE_IDLE. We won't get the second
   ViewPager.SCROLL_STATE_DRAGGING event during the second swipe.

Bug: 6021918
Change-Id: Iaca971a195144a16f7853e3555375922ad54b81b