Add tests for minor version upgrade enforcement.

Test: compiles
Test: add folder test/versioning/2.0 will make update-makefiles.sh to
fail.
Test: removing @2.3::IBar will let update-makefiles.sh to pass.
Test: Change @2.3::IBar to extend from @2.2::IFoo will let
update-makefiles.sh to fail.

Bug: 28825532
Change-Id: Iad1138b784505c903ab1049f08f6c07c38b777e1
diff --git a/tests/versioning/2.3/IBar.hal b/tests/versioning/2.3/IBar.hal
new file mode 100644
index 0000000..946d42e
--- /dev/null
+++ b/tests/versioning/2.3/IBar.hal
@@ -0,0 +1,24 @@
+/*
+ * 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.
+ */
+
+package android.hardware.tests.versioning@2.3;
+
+import @2.2::IBar;
+
+// Must extend @2.3::IBar.
+interface IBar extends @2.2::IBar {
+
+};