Adding missing license header in IMA build.gradle

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=167496569

extensions/ima/build.gradle

@@ -1,3 +1,16 @@
+// Copyright (C) 2017 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 from: '../../constants.gradle'
 apply plugin: 'com.android.library'
 
@@ -6,7 +19,7 @@ android {
     buildToolsVersion project.ext.buildToolsVersion
 
     defaultConfig {
-        minSdkVersion 14
+        minSdkVersion project.ext.minSdkVersion
         targetSdkVersion project.ext.targetSdkVersion
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
     }