Do not setenabled to false for edittext.

calling #setEnabled(false) and #setEnabled(true) for some reason
prevents the edit text from registering the backspace key. Also #setFocusable(boolean) also has the same behavior. By setting the cursor visibility, with the text input filter, we see the edit text but cannot add any characters into it and there is no cursor.

There is a visual difference here as the old behavior would grey out the
textview.

Fixes: 288469866
Test: lockout with password security method. Type some stuff, exit
bouncer and re-enter and type some stuff. Wait for lockout to finish and
type stuff and then try to hit the backspace key.

Change-Id: I5fa8e022a765c95e65c0342e68136e648d0e4ac0