update for aiohttp 3.6 (#18715)

Author: xiangyan99

sdk/core/azure-core/azure/core/pipeline/transport/_aiohttp.py

@@ -153,8 +153,8 @@ async def send(self, request: HttpRequest, **config: Any) -> Optional[AsyncHttpR
         try:
             auto_decompress = self.session.auto_decompress  # type: ignore
         except AttributeError:
-            # auto_decompress is introduced in Python 3.7. We need this to handle Python 3.6.
-            auto_decompress = True
+            # auto_decompress is introduced in aiohttp 3.7. We need this to handle Python 3.6.
+            auto_decompress = False
 
         proxies = config.pop('proxies', None)
         if proxies and 'proxy' not in config: