fix e2e test flakiness by using WaitForRollingUpdate

Signed-off-by: Nina van der Linden <[email protected]>

Author: Nina van der Linden

test/e2e/apps/statefulset.go

@@ -1014,8 +1014,7 @@ var _ = SIGDescribe("AppStatefulSetStorage", func() {
 			})
 			framework.ExpectNoError(err)
 			waitForStatus(ctx, c, kc, ss)
-			sst.WaitForStatusReplicas(ss, 2)
-			sst.WaitForStatusReadyReplicas(ss, 2)
+			sst.WaitForRollingUpdate(ss)
 
 			// verify that pods have one volume less than before
 			pods = sst.GetPodList(ss)