Memberships: Use external volume, remove one from the Helm chart.

Change-Id: Ie2afcd9ab28a12e7d6bea6375a96e00a0f63b525
diff --git a/core/installer/values-tmpl/memberships.cue b/core/installer/values-tmpl/memberships.cue
index 5fc55d1..95a2b60 100644
--- a/core/installer/values-tmpl/memberships.cue
+++ b/core/installer/values-tmpl/memberships.cue
@@ -49,19 +49,19 @@
 		}
 	}
 
+	volumes: data: size: "1Gi"
+
 	helm: {
 		memberships: {
 			chart: charts.memberships
 			values: {
-				storage: {
-					size: "1Gi"
-				}
 				image: {
 					repository: images.memberships.fullName
 					tag: images.memberships.tag
 					pullPolicy: images.memberships.pullPolicy
 				}
 				portName: _httpPortName
+				volumeClaimName: volumes.data.name
 			}
 		}
 	}