Lockscreen Notifications: some fixes

Change-Id: I3ccd2c572dcecc12ea10bde294ad2806be5a2689
LN: Some fixes & cleanup

- Fix bug that the notification is launched when a button on it is pressed
- Show new notifications first

Change-Id: I87db92a7ee4eb9329ec1ec69008e612a619d5c91
LN: Fix FC on launching hangouts notification

Change-Id: Idf411bd2b4995f0b53767e99597efd98ce0596b3
LN: beautify

Change-Id: I695846412f2b8c910f8a5cf48da2bf6ac42e124e
LN: Fix possible NPE

Change-Id: I597021f64aaee43b6964e2b6709ebd427b0a7cbc
LN: Please don't die

Change-Id: Id5d1ec1c1646fd72655aa290823fac174a79c76c