Add app-facing package test

packages/google_sign_in/google_sign_in/test/google_sign_in_test.dart

@@ -760,4 +760,22 @@ void main() {
       );
     });
   });
+
+  group('clearAuthorizationToken', () {
+    test('passes expected paramaters', () async {
+      final GoogleSignIn googleSignIn = GoogleSignIn.instance;
+
+      const String token = 'someAccessToken';
+      await googleSignIn.authorizationClient.clearAuthorizationToken(
+        accessToken: token,
+      );
+
+      final VerificationResult verification = verify(
+        mockPlatform.clearAuthorizationToken(captureAny),
+      );
+      final ClearAuthorizationTokensParams params =
+          verification.captured[0] as ClearAuthorizationTokensParams;
+      expect(params.accessToken, token);
+    });
+  });
 }