Hide unnecessary menus when launched via DIAL intent

ViewPager#getCurrentItem() returns "tabIndex" after
ViewPager#setCurrentItem(tabIndex, false), so we need to preserve
the previous value.

TESTED (using phone devices with/without a hard menu key)
- swipe actions do not corrupt menus
- tab clicks do not corrupt menus
- DIAL intent corretly shows/hides menus
- Menus aren't corrupted in Dialpad Chooser

Bug: 5118757
Change-Id: Id857a2d7ac5a007db65b20f80270a07ea527ba7f