Fix 4942542, 4590542: Password unlock fixes

Fixes issue where hint text was inappropriately shown on password unlock screen.
This was caused by TextView.setKeyListener() clearing the inputType flags.  The
workaround is to change the order of these calls.  TextView.setKeyListener()
should probably not be clearing existing inputType flags.

Fixes wake issue caused by IME events not poking the wakelock.  It now correctly pokes
the wakelock whenever the password text field changes.

Change-Id: I746b21117492c4a176f6627e7d33150e6104495e