cloudapi: set the default ostree ref for package selection

Before, this was done in the PackageSets() function.
The reason for this is that having an ostree ref affects package
selection (for example, it adds rpm-ostree).  At the package selection
phase, it doesn't matter what the ostree ref is; it is just used to
determine if a pipeline is for an ostree-based image type and it doesn't
affect non-ostree-based image types because the image functions ignore
it.

This is only needed in the cloudapi now because other places have
switched to using the new order of operations, where the manifest is
generated after the ostree commit is resolved, so it's always added when
needed.

internal/cloudapi/v2/server.go

@@ -107,6 +107,14 @@ func (s *Server) enqueueCompose(distribution distro.Distro, bp blueprint.Bluepri
 	}
 	ir := irs[0]
 
+	// NOTE(akoutsou): Image options don't have resolved ostree ref yet, but it
+	// will affect package sets if we don't add it and it's required.  This
+	// used to be done in the old PackageSets() function (which no longer
+	// exists), but now we only need it in the cloud API where things aren't
+	// done in the (new) correct order yet.
+	ir.imageOptions.OSTree = &ostree.ImageOptions{
+		ImageRef: ir.imageType.OSTreeRef(),
+	}
 	manifestSource, _, err := ir.imageType.Manifest(&bp, ir.imageOptions, ir.repositories, manifestSeed)
 	if err != nil {
 		return id, HTTPErrorWithInternal(ErrorEnqueueingJob, err)
@@ -210,6 +218,14 @@ func (s *Server) enqueueKojiCompose(taskID uint64, server, name, version, releas
 	var kojiFilenames []string
 	var buildIDs []uuid.UUID
 	for _, ir := range irs {
+		// NOTE(akoutsou): Image options don't have resolved ostree ref yet, but it
+		// will affect package sets if we don't add it and it's required.  This
+		// used to be done in the old PackageSets() function (which no longer
+		// exists), but now we only need it in the cloud API where things aren't
+		// done in the (new) correct order yet.
+		ir.imageOptions.OSTree = &ostree.ImageOptions{
+			ImageRef: ir.imageType.OSTreeRef(),
+		}
 		manifestSource, _, err := ir.imageType.Manifest(&bp, ir.imageOptions, ir.repositories, manifestSeed)
 		if err != nil {
 			return id, HTTPErrorWithInternal(ErrorEnqueueingJob, err)