gcloud authentication added

Author: rcmadhankumar

Makefile

@@ -99,3 +99,6 @@ init-buildx:
 	-docker buildx rm multiarch-multiplatform-builder
 	docker buildx create --use --name=multiarch-multiplatform-builder
 	docker run --rm --privileged multiarch/qemu-user-static --reset --credential yes --persistent yes
+	# Register gcloud as a Docker credential helper.
+	# Required for "docker buildx build --push".
+	gcloud auth configure-docker --quiet