Setup CI for builds

[srallen]

What are we doing?

CI should be setup for builds to run on pull requests using github actions. This is something we do on our other repos that use builds.

Why are we doing it?

This will increase confidence for all developers on the team to be able to review and merge pull requests and remove siloing with individuals who historically have been the only ones who run builds of the app.

Additional Context

This is a useful guide: https://ariya.io/2020/12/continuous-integration-for-react-native-apps-with-github-actions