Update aggregatedList in ListInstances to use pageToken

aggregatedList returns max 500 instances, but in the infra, we can have much
more than that. So use the pageToken to make sure we get all of the instances.

Bug: 144589609
Test: acloud delete ...
atest acloud_test
Change-Id: Ide06ab58378c222510522f7480334aab229fa4f8
diff --git a/internal/lib/gcompute_client_test.py b/internal/lib/gcompute_client_test.py
index d4f225d..690588a 100644
--- a/internal/lib/gcompute_client_test.py
+++ b/internal/lib/gcompute_client_test.py
@@ -497,7 +497,8 @@
         calls = [
             mock.call(
                 project=PROJECT,
-                filter=None),
+                filter=None,
+                pageToken=None),
         ]
         resource_mock.aggregatedList.assert_has_calls(calls)
         self.assertEqual(instances, [instance_1, instance_2])