Add request-bug and request-default fields for AbyssinicaSIL font.

Added the git and gerrit commit URLs for the addition of the AbyssinicaSIL font and it being set as the default font for Amharic (am), Geez (gez), Tigrinya (ti) and Tigre (tig).

Change-Id: I5463711cd672cf49d714fa9cf673eba15bd3ab63