chore: Add serialization for future use

app/build.gradle

 apply plugin: 'com.android.application'
 
 apply plugin: 'kotlin-android'
-
 apply plugin: 'kotlin-android-extensions'
+apply plugin: 'kotlinx-serialization'
 
 android {
     compileSdkVersion 28
@@ -26,6 +26,7 @@ android {
 dependencies {
     implementation fileTree(dir: 'libs', include: ['*.jar'])
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
+    implementation "org.jetbrains.kotlinx:kotlinx-serialization-runtime:0.13.0" // JVM dependency
     implementation 'androidx.appcompat:appcompat:1.1.0'
     implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
     implementation 'com.google.android.material:material:1.0.0'

app/src/main/java/fr/plnech/dunbar/model/Friend.kt

@@ -6,6 +6,7 @@ import android.net.Uri
 import android.provider.ContactsContract.Contacts
 import java.util.*
 
+//@Serializable
 data class Friend(val map: Map<String, String?> = mutableMapOf(), val photo: Bitmap? = null) {
     override fun toString(): String = "$name"
 

build.gradle

@@ -10,6 +10,7 @@ buildscript {
     dependencies {
         classpath 'com.android.tools.build:gradle:3.5.1'
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
+        classpath "org.jetbrains.kotlin:kotlin-serialization:$kotlin_version"
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
     }