Fix runtime version that update files are copied to in package.json

[Armster15]

Simple PR fix:

• The runtime version is set to 2 throughout the client code. However, when you run yarn expo-publish, it copies the export to updates/1 instead of updates/2. As a result, when the manifest endpoint is called, it doesn't detect the new update.
• Update the publish script to create the updates/$directory folder ahead of time to prevent errors like ./scripts/publish.sh: line 14: updates/2/1762392374/expoConfig.json: No such file or directory

Debugged live with Cedric ;)