While 422 isn't strictly a "storage full" error (that’s 413), you need double the space of the Minecraft APK + OBB files. Minecraft is roughly 850MB, but it needs 1.7GB free to unpack.
If Error 422 persists despite all troubleshooting, the Play Store manifest might be permanently glitched for your device. Download Minecraft Error 422 Android Fix
If you are trying to join a server and getting an error: While 422 isn't strictly a "storage full" error