asyncio: use test_base helpers to get metrics (#4123)

Co-authored-by: Riccardo Magliocchetti <riccardo.magliocchetti@gmail.com>

Author: anuraaga

instrumentation/opentelemetry-instrumentation-asyncio/tests/test_asyncio_future_cancellation.py

@@ -36,25 +36,20 @@ async def future_cancelled():
             asyncio.run(future_cancelled())
         except asyncio.CancelledError as exc:
             self.assertEqual(isinstance(exc, asyncio.CancelledError), True)
-        spans = self.memory_exporter.get_finished_spans()
+        spans = self.get_finished_spans()
         self.assertEqual(len(spans), 2)
         self.assertEqual(spans[0].name, "root")
         self.assertEqual(spans[1].name, "asyncio future")
 
-        metrics = (
-            self.memory_metrics_reader.get_metrics_data()
-            .resource_metrics[0]
-            .scope_metrics[0]
-            .metrics
-        )
+        metrics = self.get_sorted_metrics()
         self.assertEqual(len(metrics), 2)
 
-        self.assertEqual(metrics[0].name, "asyncio.process.duration")
+        self.assertEqual(metrics[0].name, "asyncio.process.created")
         self.assertEqual(
             metrics[0].data.data_points[0].attributes["state"], "cancelled"
         )
 
-        self.assertEqual(metrics[1].name, "asyncio.process.created")
+        self.assertEqual(metrics[1].name, "asyncio.process.duration")
         self.assertEqual(
             metrics[1].data.data_points[0].attributes["state"], "cancelled"
         )