genpolicy: support readonly hostpath

Set hostpath access based on volume mount readOnly value

Signed-off-by: Saul Paredes <saulparedes@microsoft.com>

tests/integration/kubernetes/runtimeclass_workloads/k8s-policy-rc.yaml

@@ -27,6 +27,17 @@ spec:
         volumeMounts:
           - name: host-empty-vol
             mountPath: "/host/cache"
+          - mountPath: /tmp/results
+            name: hostpath-vol
+          - mountPath: /tmp/results-read-only
+            name: hostpath-vol-read-only
+            readOnly: true
       volumes:
       - name: host-empty-vol
         emptyDir: {}
+      - name: hostpath-vol
+        hostPath:
+          path: /tmp/results
+      - name: hostpath-vol-read-only
+        hostPath:
+          path: /tmp/results-read-only