Add Kotlin dependency

app/build.gradle

@@ -1,4 +1,6 @@
 apply plugin: 'com.android.application'
+apply plugin: 'kotlin-android'
+apply plugin: 'kotlin-android-extensions'
 
 android {
     compileSdkVersion 27
@@ -81,6 +83,7 @@ def spongycastleVersion = "1.58.0.0"
 def permissionDispatcherVersion = "3.1.0"
 
 dependencies {
+    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
     implementation "com.android.support:appcompat-v7:$supportVersion"
     implementation "com.android.support:design:$supportVersion"
     implementation "com.android.support:preference-v7:$supportVersion"

build.gradle

@@ -1,5 +1,6 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 buildscript {
+    ext.kotlin_version = '1.3.11'
     repositories {
         jcenter()
         maven {
@@ -10,6 +11,7 @@ buildscript {
     }
     dependencies {
         classpath 'com.android.tools.build:gradle:3.2.0'
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
     }
 }