[Composer] Create place holder for Composer 2.4.

Create place holder for composer 2.4.

Minor: Extend DisplayCapability to include protected contents.

BUG: 135929065
Test: build
Change-Id: I9dbdb21f4a69027bedd95cd54e9c3c652bbe9006
diff --git a/graphics/composer/2.4/IComposer.hal b/graphics/composer/2.4/IComposer.hal
new file mode 100644
index 0000000..34801da
--- /dev/null
+++ b/graphics/composer/2.4/IComposer.hal
@@ -0,0 +1,34 @@
+/*
+ * Copyright 2019 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.
+ */
+
+package android.hardware.graphics.composer@2.4;
+
+import IComposerClient;
+
+import @2.1::Error;
+import @2.3::IComposer;
+
+interface IComposer extends @2.3::IComposer {
+
+    /**
+     * Creates a v2.4 client of the composer. Supersedes @2.3::createClient.
+     *
+     * @return error is NONE upon success. Otherwise,
+     *         NO_RESOURCES when the client could not be created.
+     * @return client is the newly created client.
+     */
+    createClient_2_4() generates (Error error, IComposerClient client);
+};