🐮 Add dummy junit targets so that GYP & GN have the same targets

components/invalidation.gypi

Index: components/invalidation.gypi
diff --git a/components/invalidation.gypi b/components/invalidation.gypi
index 0ab96ae0c6dc77a97481a5f77f2b76fce8442071..96e36744d741fccb48500d57c944437bd385f1e6 100644
--- a/components/invalidation.gypi
+++ b/components/invalidation.gypi
@@ -247,6 +247,21 @@
           },
           'includes': [ '../build/jni_generator.gypi' ],
         },
+        {
+          'target_name': 'components_invalidation_impl_junit_tests',
+          'type': 'none',
+          'dependencies': [
+            '../testing/android/junit/junit_test.gyp:junit_test_support',
+          ],
+          'variables': {
+            'main_class': 'org.chromium.testing.local.JunitTestMain',
+            'src_paths': [
+               '../testing/android/junit/DummyTest.java',
+            ],
+            'wrapper_script_name': 'helper/<(_target_name)',
+          },
+          'includes': [ '../build/host_jar.gypi' ],
+        },
       ],
      },
     ],