conversation: add emoji preference

.../src/main/java/cx/ring/client/ContactDetailsActivity.java

...src/main/java/cx/ring/client/EmojiChooserBottomSheet.java

...src/main/java/cx/ring/fragments/ConversationFragment.java

.../java/cx/ring/tv/conversation/TvConversationFragment.java

ring-android/app/src/main/res/layout/item_contact_action.xml

ring-android/app/src/main/res/layout/item_emoji.xml

ring-android/app/src/main/res/values/arrays.xml

...main/java/cx/ring/conversation/ConversationPresenter.java

.../src/main/java/cx/ring/conversation/ConversationView.java

...bringclient/src/main/java/cx/ring/model/Conversation.java