Bug 974864: [MMS]Pick recipient(email adress) up from contacts app

https://bugzilla.mozilla.org/show_bug.cgi?id=974864
also, I need a unit test to test this. Please add a test in the suite `Contact Picker Behavior(contactPickButton)`. The goal is to check that we call the right MozActivity depending on Settings.supportEmailRecipient value (so we need new 2 tests, given that we have sadly no test for this right now).

You can use the array `MockMozActivity.calls` to know how the constructor was called. Probably sinon would work too.