LatinIME: Customize features for regional package.

Add new feature to support:
- Customize auto correction type of input method LatinIME.
- Make the button in the lower right corner of the keyboard to be
  Enter button.

By default they are not enabled, they could be enabled in the
operator data package overlay if needed.

Change-Id: I7198bf600eab499de44c73bf4b1e6a761a82410b
CRs-Fixed: 1043367