Fix crash on opening map multiple times

android/app/build.gradle

@@ -86,4 +86,5 @@ flutter {
 
 dependencies {
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
+    implementation "com.google.android.gms:play-services-maps:$maps_version"
 }

android/app/src/main/kotlin/com/gskinner/wonders/MainActivity.kt

@@ -1,6 +1,15 @@
 package com.gskinner.flutter.wonders
 
+import android.os.Bundle
+import com.google.android.gms.maps.MapsInitializer
+import com.google.android.gms.maps.OnMapsSdkInitializedCallback
 import io.flutter.embedding.android.FlutterActivity
 
-class MainActivity: FlutterActivity() {
+class MainActivity : FlutterActivity(), OnMapsSdkInitializedCallback {
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        MapsInitializer.initialize(applicationContext, MapsInitializer.Renderer.LATEST, this)
+    }
+
+    override fun onMapsSdkInitialized(p0: MapsInitializer.Renderer) {}
 }

android/build.gradle

@@ -1,5 +1,7 @@
 buildscript {
     ext.kotlin_version = '1.6.10'
+    ext.maps_version = '18.1.0'
+
     repositories {
         google()
         mavenCentral()