ci: fix log template pipeline variable expansion (#4385)

fix log template pipeline variable expansion

$(acnLogs) is a pipeline variable, $acnLogs is a bash variable
echo "##vso[task.setvariable variable=acnLogs]$acnLogs" sets the pipeline var
$acnLogs the bash variable was not set in the task, so it resolved to empty (bad)
$(acnLogs) is replaced with the pipeline variable val prior to the script running

Author: QxBytes

.pipelines/templates/log-template.yaml

@@ -112,12 +112,12 @@ steps:
         if [ -z ${array[0]} ]; then
           echo "There are no kube-system pods in a non-ready state."
         else
-          mkdir -p $acnLogs/${{ parameters.os }}non-ready
-          echo "Directory created: $acnLogs/${{ parameters.os }}non-ready"
+          mkdir -p $(acnLogs)/${{ parameters.os }}non-ready
+          echo "Directory created: $(acnLogs)/${{ parameters.os }}non-ready"
           echo "Capturing failed pods"
           for pod in $podList; do
-            kubectl describe pod -n kube-system $pod > $acnLogs/${{ parameters.os }}non-ready/$pod.txt
-            echo "$acnLogs/${{ parameters.os }}non-ready/$pod.txt"
+            kubectl describe pod -n kube-system $pod > $(acnLogs)/${{ parameters.os }}non-ready/$pod.txt
+            echo "$(acnLogs)/${{ parameters.os }}non-ready/$pod.txt"
           done
         fi
       displayName: Failure Logs