Bug 1094550 - Unable to create a new account because Year of Birth
dropdown doesn't work.
 - Create a value selector overlay to listen to the event for showing value selector for trusted
   UI.
 - Let trusted UI module init its own value selector controller.
Merge pull request #26054 from RudyLu/valueSelector/Bug1094550-forTrusted_UI

Bug 1094550 - Unable to create a new account because Year of Birth dropdown
r=alivedise.