Keyguard: Enhancement for message lockscreen target

When user sets "Default SMS app" as a third-party apk in settings, it
should enter user preferred app directly without pop up to select app.

By original design, the configuration of "Default SMS app" just affects
the SENDTO action. So, for a workaround, will check this in keyguard when
launch messaging.

CRs-Fixed: 724349

Change-Id: I969889c2f9b9b28e653026d3edebebc5c2caacca