Update Light extension example to match docs.

This light extension example was more of a POC. Now it
matches the suggestions for minor version requirements
and vendor extensions that are spelled out in publically
available documentation.

This includes things like:
- taking advantage of namespacing rather than renaming things
- adding documentation when extension differs from what a minor
  version extension should be
- importing things specifically rather than dumping namespaces
  into the types.hal file

Test: compilation only -- it doesn't do anything
Change-Id: Ia1bf9baaddcb630cc1b6cd4fe272def0c7c492e9
Fixes: 67787567
diff --git a/tests/extension/light/2.0/ILight.hal b/tests/extension/light/2.0/ILight.hal
new file mode 100644
index 0000000..94781c0
--- /dev/null
+++ b/tests/extension/light/2.0/ILight.hal
@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// Would normally be 'vendor.example.extension.light@2.0' however, this is
+// a google extension example. A vendor extension should also live in the
+// vendor partition.
+package android.hardware.tests.extension.light@2.0;
+
+import android.hardware.light@2.0::ILight;
+import android.hardware.light@2.0::Status;
+import android.hardware.light@2.0::Type;
+
+interface ILight extends android.hardware.light@2.0::ILight {
+
+    /**
+     * Set the provided lights to the provided values.
+     *
+     * If this was a minor version extension, the recommended
+     * name would be setLight_2_1.
+     *
+     * @param type logical light to set
+     * @param state describes what the light should look like.
+     * @return status result of applying state transformation.
+     */
+    setLightExt(Type type, LightState state) generates (Status status);
+};