mount dockersock for docker in docker

.harness/firebase-deploy.yaml

@@ -5,6 +5,10 @@ spec:
     - name: build
       type: ci
       spec:
+        volumes:
+        - name: dockersock
+          spec: {}
+          type: temp
         steps:
           - name: debug
             type: run
@@ -20,6 +24,9 @@ spec:
             spec:
               name: docker
               container: registry-app.inhome.blapointe.com:5001/docker:latest
+              mount:
+              - name: dockersock
+                path: /var/run
               shell: sh
               script: |
                 set -ueo pipefail