updated gradle

.gitignore

 android/react-native-permissions.iml
 android/build
+android/.idea
+npm-debug.log
+gradlew
+gradle-wrapper.properties
+gradle-wrapper.jar
+local.properties
+gradlew.bat
+android.iml

Example/android/app/build.gradle

 
     defaultConfig {
         applicationId "com.example"
-        minSdkVersion 22
+        minSdkVersion 21
         targetSdkVersion 23
         versionCode 1
         versionName "1.0"

Example/android/build.gradle

         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:1.3.1'
+        classpath 'com.android.tools.build:gradle:2.1.2'
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files

Example/android/gradle/wrapper/gradle-wrapper.properties

+#Fri Feb 03 16:27:32 CET 2017
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-2.4-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-2.10-all.zip