Added spotless

app/build.gradle

@@ -120,4 +120,13 @@ dependencies {
 
 if (firebaseEnabled()) {
     apply plugin: 'com.google.gms.google-services'
+}
+
+apply plugin: "com.diffplug.gradle.spotless"
+spotless {
+    java {
+        target '**/*.java'
+        googleJavaFormat('1.6').aosp()
+        removeUnusedImports()
+    }
 }

build.gradle

@@ -5,10 +5,14 @@ buildscript {
         google()
         jcenter()
         mavenCentral()
+        maven {
+            url "https://plugins.gradle.org/m2/"
+        }
     }
     dependencies {
         classpath 'com.android.tools.build:gradle:3.2.1'
         classpath 'com.google.gms:google-services:3.1.0'
+        classpath "com.diffplug.spotless:spotless-plugin-gradle:3.16.0"
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files