Android React Native build improvements

IMO, this new RN build is pretty cool. But, it needs some improvements, like:

- better performance: it's pretty poorly optimized

- missing image compression feature: was pretty useful sometimes

- weird scrolling: sometimes scrolling gets stuck and it feels weird

- channel names get all messed up when there is a specific unicode symbol in them

- non-nitro emojis look weird in custom statuses: they use system emoji instead of twemoji and they are too big

- i don't like the fact that camera roll gets cut out and it forces you to use DocumentsUI to find a image: it was far better before

- i also don't like that unusable emojis are shown in emoji picker: before they were hidden

Overall, i think that this new build is a move in good direction, but i hope that some of the bugs that are still there will be ironed out.