Improve the credibility of the test

src/python/grpcio_tests/tests_aio/unit/channel_argument_test.py

@@ -93,7 +93,7 @@ class TestChannelArgument(AioTestBase):
         random.seed(_RANDOM_SEED)
 
     async def test_server_so_reuse_port_is_set_properly(self):
-        for _ in range(_NUM_SERVER_CREATED):
+        async def test_body():
             fact, options = random.choice(_OPTIONS)
             server = aio.server(options=options)
             try:
@@ -109,6 +109,11 @@ class TestChannelArgument(AioTestBase):
             finally:
                 await server.stop(None)
 
+        # Creating a lot of servers concurrently
+        await asyncio.gather(
+            *(test_body() for _ in range(_NUM_SERVER_CREATED))
+        )
+
     async def test_client(self):
         aio.insecure_channel('[::]:0', options=_TEST_CHANNEL_ARGS)