Fix object storage uploads not working with AWS v2

Because we were passing query strings as symbols, the fog-aws storage
driver was omitting the uploadId and partNumber query strings
from the signature in multipart uploads. This fix makes AWS and Ceph work with
v2 signatures.

See: https://github.com/fog/fog-aws/blob/v3.0.0/lib/fog/aws/storage.rb#L733

Closes https://gitlab.com/gitlab-org/gitlab-workhorse/issues/181

changelogs/unreleased/sh-fix-multipart-upload-signed-urls.yml

+---
+title: Fix object storage uploads not working with AWS v2
+merge_request: 21731
+author:
+type: fixed

lib/object_storage/direct_upload.rb

@@ -89,7 +89,7 @@ module ObjectStorage
         method: 'PUT',
         bucket_name: bucket_name,
         object_name: object_name,
-        query: { uploadId: upload_id, partNumber: part_number },
+        query: { 'uploadId' => upload_id, 'partNumber' => part_number },
         headers: upload_options
       }, expire_at)
     end
@@ -100,7 +100,7 @@ module ObjectStorage
         method: 'POST',
         bucket_name: bucket_name,
         object_name: object_name,
-        query: { uploadId: upload_id },
+        query: { 'uploadId' => upload_id },
         headers: { 'Content-Type' => 'application/xml' }
       }, expire_at)
     end
@@ -111,7 +111,7 @@ module ObjectStorage
         method: 'DELETE',
         bucket_name: bucket_name,
         object_name: object_name,
-        query: { uploadId: upload_id }
+        query: { 'uploadId' => upload_id }
       }, expire_at)
     end

spec/lib/object_storage/direct_upload_spec.rb

@@ -83,6 +83,16 @@ describe ObjectStorage::DirectUpload do
         expect(subject[:MultipartUpload][:AbortURL]).to start_with(storage_url)
         expect(subject[:MultipartUpload][:AbortURL]).to include('uploadId=myUpload')
       end
+
+      it 'uses only strings in query parameters' do
+        expect(direct_upload.send(:connection)).to receive(:signed_url).at_least(:once) do |params|
+          if params[:query]
+            expect(params[:query].keys.all? { |key| key.is_a?(String) }).to be_truthy
+          end
+        end
+
+        subject
+      end
     end
     shared_examples 'a valid upload without multipart data' do