demo: add missing file for Kadalu CSI demo (#12336)

demo/csi/kadalu-csi/volume.hcl

@@ -0,0 +1,30 @@
+# Unfortunately 'variable' interpolation isn't supported in volume spec
+# so, parameters has to be supplied again
+
+id = "csi-test"
+
+name = "csi-test"
+
+type = "csi"
+
+plugin_id = "kadalu-csi"
+
+capacity_min = "200M"
+
+capacity_max = "1G"
+
+capability {
+  access_mode     = "multi-node-multi-writer"
+  attachment_mode = "file-system"
+}
+
+parameters {
+  kadalu_format = "native"
+
+  # Below parameters needs to be replaced correctly based on
+  # json file supplied during controller/nodeplugin job
+  storage_name = "POOL"
+
+  gluster_hosts   = "GHOST"
+  gluster_volname = "GVOL"
+}