I tested this PR with my GoToSocial account. When requesting the /api/v1/custom_emojis endpoint, GoToSocial still returns a 401 error, displaying errors=Error #01: token not supplied\n

I changed the version number, and the version number displayed in the final built APK also changed, so I guess my build process is fine.

Maybe we don't need to check if the user's instance is GoToSocial? As far as I know, making a request to the custom emoji endpoint of a Mastodon instance with an Auth Token doesn't have side effects. Also, it seems that Mastodon instances with AUTHORIZED_FETCH enabled require an access token when requesting the custom emoji endpoint.

I'm willing to continue testing this PR or provide a corresponding GoToSocial account for further testing.

mastodon#948