amazon-image: Increase diskSize 3 -> 4GB

Disk usage of the image has risen considerably since last release. We
still need to investigate the cause in detail. Increasing it for now
prevents build failures at least.

Author: phaer

nixos/maintainers/scripts/ec2/amazon-image.nix

@@ -83,7 +83,7 @@ in
 
   # Use a priority just below mkOptionDefault (1500) instead of lib.mkDefault
   # to avoid breaking existing configs using that.
-  config.virtualisation.diskSize = lib.mkOverride 1490 (3 * 1024);
+  config.virtualisation.diskSize = lib.mkOverride 1490 (4 * 1024);
   config.virtualisation.diskSizeAutoSupported = !config.ec2.zfs.enable;
 
   config.system.nixos.tags = [ "amazon" ];