Mms: prevent reply text being wiped from QMPopup when new msg arrives

If user starts typing a reply in the QuickMessage Popup, and another msg
arrives, the entered text was wiped. This commit saves the current reply
text, before adding/updating the new message, so that is doesn't get lost

Change-Id: I7aa4a488b233ed7554ec589fae0d615b18e3502c
Mms: Need to hide keyboard when the Popup loses focus

Previous commit, prevented QuickMessage text from disappearing, but was leaving
the keyboard open, so user could continue to type. Unfortunately, the EditText
loses focus (not sure if that can be changed?), so the typed text goes nowhere
and causes confusion.

This commit will hide the keyboard, so user will need to reselect the EditText
field first to redisplay the keyboard and continue typing.

Change-Id: I4869392b16be015ab9a8cd99bf3f95f0e86b74ad
Don't show quick message popup over secure lockscreen.

Doing so allows bypassing the lockscreen.

Change-Id: I8a49395954ba1e50415285531ebe75e2c4343c1c