Deprecating/Supporting one platform version also deprecate/support other platform version
When user add app version configs for platforms (Android & iOS) with same versions (E.g. 2.2.0) and deprecate/support one version but not the other. App also deprecate/support other platform version.
Add app version config lets say 2.5.0 for platform android and mark it as deprecated (by selecting expired date for the platform version). Add one more app version config lets say 2.5.0 for platform iOS (Supported). iOS app will not allow user to login showing 'Your version of the app is no longer supported. Update to the latest version to login.' Additionally, remove the entry from config for iOS and try logging in both platforms. Android and iOS both will allow user to login.