Add color used by the emoji keyboard; Load emojis; Add emoji related layout; Add all emoji related code

Merge branch 'feature/document-upload' of https://github.com/filipedelimabrito/Rocket.Chat.Android into filipedelimabrito-feature/document-upload

Merge branch 'develop-2.x' of https://github.com/RocketChat/Rocket.Chat.Android into feature/document-upload

[NEW][WIP] Message actions - Reply, Quote, Copy, Delete, Edit and Pin/Unpin

[DOCS] Build details in README.md