Make group editor usable in landscape

In both landscape/portrait
- Disable the IME extraction mode.
(We probably don't have to do it for portrait, but just for consistency.)

In landscape
- Remove the accout header.
- Horizontally align the group name field and the member name field,
much like the tablet layout.

- Also un-bold group name, per UX request

Bug 5265688

Change-Id: Ic6a39d61f91d21bbf820ee90e807b677ac5d3535