Sync emojicompat changes to aosp-master

This is a revert of the revert created to fix a build failure.

This includes the refactor of emoji-compat and emoji-compat-flatbuffers
for the emoji2 project.

Merged-in: I01d37a9ea45ea07dc5c1f96f5297a038d9b149ad
Merged-in: Iedf596f138ea92b1ef15aea361b345d2968d4807
Merged-in: If2d4373bdb28cf437d7e1ee1214fdb90a6aa4d00
Merged-in: I677e251377739b6162eeadeb0f483df479520741
Merged-in: Id4d36af09ca90c0edd1cc837918e3c89860deabb
Merged-in: If99657b7973dd881a2994e93cb02bb11f40f35ab
Merged-in: Ic6472dd22e94ba8a565b22db57ed36b70e19d3e6
Merged-in: I23bb6a7bc40bb9e27159ed2312b413f183cc17b7

Bug: b/191882101

Previous revert: aosp/1748232

Test: ran ./createfont.py
Test: m fontchain_lint
Change-Id: I0de0be2099c37856caee97dcd761964665e128a9
17 files changed