Move Google Services files encoding and decoding to EAS

[zaniluca]

Summary

EAS now allows for automatic parsing of encoded files, we may want to use that instead of our manual base64 encoding and decoding for GoogleServices.json

Todo / ordered steps

• Upload GoogleServices.json to eas via eas secret:create --scope project --name GOOGLE_SERVICES_JSON --type file --value ./path/to/google-services.json
• In app.config.json add the config file from the environment variables

  android: {
    googleServicesFile: process.env.GOOGLE_SERVICES_JSON,
    // ...
  },

• Remove the scripts in package.json
• Remove the commands in the build workflows
• Test that both the local build and the eas build works

Possible impacts/side effects on existing features

TBD

Additional notes

Docs: https://docs.expo.dev/build-reference/variables/#how-to-upload-a-secret-file-and