If skin tone is specified, the base emoji should be emoji style even
if it is text presentation default emoji.
This patch also removes wrong test case which expects default emoji
presentation but it is controlled by family order in /etc/fonts.xml
and there is no special logic for default presentation in minikin.
Thus the default presentation unit test should not be in minikin.
Bug: 27342346
Change-Id: I74a2b2feab4d559535049e368cfd833063cce81c