CreateImageWizard: use non-deprecated image type aliases

'ami' was deprecated a while ago, and is kept around as an alias of
'aws'. Same with 'vhd' and 'azure', and 'vhd' and 'gcp'.

This maintains support for the old aliases where necessary.

src/test/Components/ShareImageModal/ShareImageModal.test.js

@@ -22,7 +22,7 @@ const mockComposes = {
         image_requests: [
           {
             architecture: 'x86_64',
-            image_type: 'ami',
+            image_type: 'aws',
             upload_request: {
               type: 'aws',
               options: {