Bug972573, The selection screen for adding a contact with multiple phone...

... numbers to a SMS message lacks a cancel, back, or 'x' button

Change from ValueSelector to ActionMenu

https://bugzilla.mozilla.org/show_bug.cgi?id=972573
Oh, I was tricked by not seeing you inserting a CSS file related to building blocks in this PR, but it's there on LOC 18, I'm sorry.