Add Gradle compilation support

- Removed obsolete proguard flags.
- Added {min,target}SdkVersion info to manifest.

Change-Id: Id482b58d16d4c38833d50da557a16a959ec9ff12
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index 81a13ba..ff26102 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -1,3 +1,20 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  Copyright (C) 2015 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.
+  -->
+
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
         package="com.android.deskclock"
         android:versionCode="303" android:versionName="3.0.3">
@@ -5,6 +22,8 @@
     <original-package android:name="com.android.alarmclock" />
     <original-package android:name="com.android.deskclock" />
 
+    <uses-sdk android:minSdkVersion="21" android:targetSdkVersion="22" />
+
     <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
     <uses-permission android:name="android.permission.WAKE_LOCK"/>
     <uses-permission android:name="android.permission.VIBRATE"/>
@@ -242,4 +261,3 @@
         </service>
     </application>
 </manifest>
-