Always include default system IMEs for restricted profiles

Add default IMEs to an exclusion set so that we don't include them in the
list of toggleable system apps that we show the user.

Bug: 8724246

Unrevert the change to include disabled apps, as the above change fixes the
reason for the revert.

Bug: 8713202

Change-Id: Ifced841ad3bfbde33d2403356216dd1749b7fa9a