Merge pull request #21712 from lidizheng/fix-import

[Aio] Fix a segfault in check connectivity state

src/python/grpcio/grpc/_cython/_cygrpc/aio/channel.pyx.pxi

@@ -53,10 +53,13 @@ cdef class AioChannel:
 
     def check_connectivity_state(self, bint try_to_connect):
         """A Cython wrapper for Core's check connectivity state API."""
-        return grpc_channel_check_connectivity_state(
-            self.channel,
-            try_to_connect,
-        )
+        if self._status == AIO_CHANNEL_STATUS_DESTROYED:
+            return ConnectivityState.shutdown
+        else:
+            return grpc_channel_check_connectivity_state(
+                self.channel,
+                try_to_connect,
+            )
 
     async def watch_connectivity_state(self,
                                        grpc_connectivity_state last_observed_state,
@@ -90,8 +93,8 @@ cdef class AioChannel:
             return True
 
     def close(self):
-        grpc_channel_destroy(self.channel)
         self._status = AIO_CHANNEL_STATUS_DESTROYED
+        grpc_channel_destroy(self.channel)
 
     def call(self,
              bytes method,