add branch ref from CI

.pipelines/templates/template-push-images-to-acr.yml

@@ -9,5 +9,7 @@ steps:
     export RP_IMAGE_ACR=${{ parameters.rpImageACR }}
 
     az acr login --name "$RP_IMAGE_ACR"
+    # azure checkouts commit, so removing master reference when publishing image
+    export BRANCH=$(Build.SourceBranchName)
     make publish-image-aro
   displayName: ⚙️ Build and push images to ACR

Makefile

@@ -1,6 +1,5 @@
 SHELL = /bin/bash
 COMMIT = $(shell git rev-parse --short HEAD)$(shell [[ $$(git status --porcelain) = "" ]] || echo -dirty)
-BRANCH = $(shell git rev-parse --abbrev-ref HEAD)
 ARO_IMAGE ?= ${RP_IMAGE_ACR}.azurecr.io/aro:$(COMMIT)
 
 aro: generate