fix: use .read() instead of .content.read() in aiohttp transport

Using .read() is more robust when working with caching libraries like
aiohttp-client-cache, which may cause .content.read() to return empty
bytes on subsequent reads. .read() ensures the full body is returned.

Fixes #1248

Author: google-labs-jules[bot]

google/auth/transport/_aiohttp_requests.py

@@ -79,7 +79,7 @@ def data(self):
 
     async def raw_content(self):
         if self._raw_content is None:
-            self._raw_content = await self._response.content.read()
+            self._raw_content = await self._response.read()
         return self._raw_content
 
     async def content(self):

tests_async/transport/test_aiohttp_requests.py

@@ -40,7 +40,7 @@ def test__is_compressed_not(self):
     @pytest.mark.asyncio
     async def test_raw_content(self):
         mock_response = mock.AsyncMock()
-        mock_response.content.read.return_value = mock.sentinel.read
+        mock_response.read.return_value = mock.sentinel.read
         combined_response = aiohttp_requests._CombinedResponse(response=mock_response)
         raw_content = await combined_response.raw_content()
         assert raw_content == mock.sentinel.read
@@ -53,7 +53,7 @@ async def test_raw_content(self):
     @pytest.mark.asyncio
     async def test_content(self):
         mock_response = mock.AsyncMock()
-        mock_response.content.read.return_value = mock.sentinel.read
+        mock_response.read.return_value = mock.sentinel.read
         combined_response = aiohttp_requests._CombinedResponse(response=mock_response)
         content = await combined_response.content()
         assert content == mock.sentinel.read