Lookup glyph from color emoji font before and after ZWJ.

Unicode recommends that the zwj sequences should be emoji presentation
even if they don't have the proper U+FE0F. Thus always lookup the glyph
for the code point before and after zwj as if they have a U+FE0F
variation selector.

Bug: 30056627
Change-Id: I03958a92337eaba4a8dd9c5be824b2665aa4a103
8 files changed
tree: 2e50cfc45233ad1613f7cc9f397dbb805e9d4936
  1. app/
  2. doc/
  3. include/
  4. libs/
  5. sample/
  6. tests/
  7. tools/