* For each of incoming, outgoing, exchange fragment, create a "settings
mode" which slightly alters the layout for use in AccountSettingsXL.
* Build a settings mode wrapper layout around the basic fragment
* Add new constructor to set "settings mode" and select layout
* Add wiring for cancel/next buttons in the fragment
* AccountSettingsXL configures each fragment in its settings mode
* Remove old actionbar "Next" options (no longer needed)
TODO: Pixel perfect adjustments, colors, fonts, etc.
Bug: 3188951
Change-Id: Iba26281b214333db301dd40d6c016b6c5a932c2d
