Update build-and-push workflow

Ensure that the build of the operator on the lcore-migration branch is
pushed to quay.io with distinctive tag so taht we can differentiate
between builds from lcore-migration and those from main.

Author: lpiwowar

.github/workflows/build-and-push.yaml

@@ -3,7 +3,7 @@ name: "Build and push operator container image"
 on:
   push:
     branches:
-      - main
+      - lcore-migration
   workflow_dispatch: {}
 
 env:
@@ -32,7 +32,13 @@ jobs:
           BUNDLE_IMAGE=${IMAGE_TAG_BASE}-bundle:v${VERSION}
           CATALOG_IMAGE=${IMAGE_TAG_BASE}-catalog:v${VERSION}
 
-          LATEST_TAG=latest
+          # `main` branch    -> `latest` tag
+          # any other branch -> `[branch-name]-latest` tag
+          if [[ "${{ github.ref_name }}" == "main" ]]; then
+            LATEST_TAG=latest
+          else
+            LATEST_TAG=${{ github.ref_name }}-latest
+          fi
           OPERATOR_IMAGE_LATEST=${IMAGE_TAG_BASE}:${LATEST_TAG}
           BUNDLE_IMAGE_LATEST=${IMAGE_TAG_BASE}-bundle:${LATEST_TAG}
           CATALOG_IMAGE_LATEST=${IMAGE_TAG_BASE}-catalog:${LATEST_TAG}