Revert "SearchView focus should be preserved in split-screen."

This reverts commit 96d68d45.

Reason for revert: This CL fixed the bug but introduced a new one as described in bug 31298450 comment#10
Bug: 31298450
Bug: 31444175
Test: Manually done as follows
  1. Open system settings.
  2. Tap "System"
  3. Tap "Languages & input"
  4. Tap "Languages"
  6. Tap "Add a language"
  7. Select "English"
  8. Tap the back button on the NavBar
  9. Make sure that the user is navigate back to "Add a language" screen.
Change-Id: I1c98476e962a2d767ec8ed6462c50715a95be9bc