Less intrusive VPN dialog and other UX tweaks.

-The ability to launch VPNs is now sticky; once approved by the user,
further approvals are not needed UNLESS the connection is revoked in
Quick Settings.

-The old persistent notification has been removed in favor of the new
Quick Settings UI.

-The name of the VPN app is now pulled from the label of the VPN
service rather than the app itself, if one is set.

Bug: 12878887
Bug: 16578022
Change-Id: I102a14c05db26ee3aef030cda971e5165f078a91
22 files changed