Update isEmoji for Unicode 13.

As ICU is updated to 66.1 this consists of just removing all the
special case logic that ws added when Unicode 12 support was added
ahead of ICU support.

Test: minikin_tests
Bug: 151964652

Change-Id: I381d582ff33eb825c6f0c8de391d0baaa5d78a4a
(cherry picked from commit 7f22730fca0a4e0cc5207ac639a46b1925a1f4e4)
2 files changed