Use hint text to position handle / floating tool bar popups

In situations where the hint text does not match the direction of
the TextView's primary selection, when you copy text, and long press
in that EditText to paste, the cursor would use the direction of the
hint text to be placed, whereas the handle and floating tool bar
used the TextView's direction to be placed so they wouldn't match.

This CL updates the handle view and floating tool bars to use the
hint text direction when appropriate.

Bug: 21480429
Change-Id: I8090a5b2738c035522c307535ffa165ca024e811