Fix a bug with enterTouchMode removing focus

 Bug: 6347083
 Fix an issue where enterTouchMode would remove focus from the
 view that already has focus and is focusableInTouchMode. This
 causes issues with WebView, as it updates internal state when
 losing and gaining focus.

Change-Id: I5c1f72cc08baf3445e2be9e0496606a53fb9929e