fix: missing scheme on runtime when using expo-updates

[achorein]

Summary

When using expo-updates in a release build, sometimes the scheme is no availaible in the runtime (Constants.expoConfig?.scheme)

similar issue : https://github.com/expo/custom-expo-updates-server/issues/12

Todo

• fallback to Linking.createUrl if missing
• Provide a option to force scheme value

    useShareIntent({
      scheme: "exposhareintentexample",
    });

    <ShareIntentProvider
      options={{
          scheme: "exposhareintentexample",
      }}
    >

• Update react-navigation demo to replace Constants.expoConfig?.scheme in custom linking configuration
• Update README.md

Issue

Fixes #46

Testing

https://docs.expo.dev/eas-update/debug-advanced/#ios-local-builds

yarn ios ---configuration Release

[felixaa]

Awesome job, and great find! I guess another possibility could be to include the app scheme in the plugin config 🤔 . But I think your suggestion putting it in the config options makes sense

        [
            'expo-share-intent',
            {
                iosAppScheme: 'myAwesomeApp'
                iosActivationRules: { ... },
                androidIntentFilters: [ ... ],
            },
        ],

[achorein]

Indeed, we should be able to get the scheme from the app config.

The plugin already have the scheme but it run on the prebuild phase and only manage native code and generation for build.

Need to find a solution for the runtime without adding a boller plate in the native code.

I will try to use the Linking.createUrl() API