cloud: temporary stop progress before uploading

The upload code is currently using a plain "pb.ProgressBar" and
this is tested as part of our integration test. This will collide
with our own progress implementation. For now workaround this by
stopping our own progress and let plain "pb" takeover.

I was tempted to fix it right away but the PR with the progress
is already relatively big so I opted for a followup.

bib/cmd/bootc-image-builder/cloud.go

@@ -34,7 +34,7 @@ func uploadAMI(path, targetArch string, flags *pflag.FlagSet) error {
 	// similar. Eventually we may provide json progress here too.
 	var pbar *pb.ProgressBar
 	switch progress {
-	case "text":
+	case "", "plain", "term":
 		pbar = pb.New(0)
 	}
 

bib/cmd/bootc-image-builder/main.go

@@ -487,6 +487,11 @@ func cmdBuild(cmd *cobra.Command, args []string) error {
 
 	pbar.SetMessagef("Build complete!")
 	if upload {
+		// XXX: pass our own progress.ProgressBar here
+		// *for now* just stop our own progress and let the uploadAMI
+		// progress take over - but we really need to fix this in a
+		// followup
+		pbar.Stop()
 		for idx, imgType := range imgTypes {
 			switch imgType {
 			case "ami":