Ignore non-avaiable volumes in findMatchingVolume: update tests

- Use VolumeAvaiable instead of empty or pending phase in tests
- Add a test case to verify findMatchingVolume will not choose
  non-avaiable PVs if it's not pre-bind
- Add a test case to verify syncClaim will not choose non-avaibalbe PVs
  if it's not pre-bind

pkg/controller/volume/persistentvolume/framework_test.go

@@ -1222,6 +1222,9 @@ func (plugin *mockVolumePlugin) Provision(selectedNode *v1.Node, allowedTopologi
 					GCEPersistentDisk: &v1.GCEPersistentDiskVolumeSource{},
 				},
 			},
+			Status: v1.PersistentVolumeStatus{
+				Phase: v1.VolumeAvailable,
+			},
 		}
 	}