[google_maps] Relax the Android renderer requset test (flutter#3364)

Updates the "initialized with latest renderer" test to just test that
the rest resulted in some valid response, since we can't actually
control what the server returns; the request is non-binding, and there
are cases where (e.g., depending on the device details) the legacy
renderer will be returned regardless.

packages/google_maps_flutter/google_maps_flutter_android/example/integration_test/latest_renderer_test.dart

@@ -22,7 +22,14 @@ void main() {
   });
 
   testWidgets('initialized with latest renderer', (WidgetTester _) async {
-    expect(initializedRenderer, AndroidMapRenderer.latest);
+    // There is no guarantee that the server will return the latest renderer
+    // even when requested, so there's no way to deterministically test that.
+    // Instead, just test that the request succeeded and returned a valid
+    // value.
+    expect(
+        initializedRenderer == AndroidMapRenderer.latest ||
+            initializedRenderer == AndroidMapRenderer.legacy,
+        true);
   });
 
   testWidgets('throws PlatformException on multiple renderer initializations',