Add Gradle compilation support

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

Change-Id: Id482b58d16d4c38833d50da557a16a959ec9ff12
diff --git a/build.gradle b/build.gradle
new file mode 100644
index 0000000..8e90ddd
--- /dev/null
+++ b/build.gradle
@@ -0,0 +1,37 @@
+/*
+* 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.
+*/
+
+apply plugin: "com.android.application"
+
+android {
+    sourceSets {
+        main {
+            manifest.srcFile "AndroidManifest.xml"
+            java.srcDir "src"
+            res.srcDir "res"
+            assets.srcDir "assets"
+        }
+    }
+
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_7
+        targetCompatibility JavaVersion.VERSION_1_7
+    }
+
+    dependencies {
+        compile project(":support-v13")
+    }
+}