Added redundant focusable attribute read in TextView

Some apps were relying on TextView favoring focusable over
focusableInTouchMode when they were explicitly set to
opposite values in XML (usually because they start with an
EditText and only set focusable=false). This behavior is
undefined (and is, in-fact opposite to every other View).
In order to keep backwards-compatibility, this restores
the old behavior.

Bug: 36497135
Bug: 37916052
Test: Tested those apps and they behave like they used to.
      TextView CTS still passes.

Change-Id: I65bd1b343a6dfb087f41c9fc8af4b5c1e4c71493