Update project structure

This was done in comparison to a newly created flutter project. Notably
this included migrating to AndroidX, updating Gradle and Kotlin and
introducing a new .gitignore file in the android subdirectory.

.gitignore

@@ -24,50 +24,8 @@
 .dart_tool/
 pubspec.lock
 .flutter-plugins
+.flutter-plugins-dependencies
 .packages
 .pub-cache/
 .pub/
 /build/
-
-# Android related
-**/android/.gradle
-**/android/gradle
-**/android/captures/
-**/android/gradlew
-**/android/gradlew.bat
-**/android/local.properties
-**/android/**/GeneratedPluginRegistrant.java
-
-# iOS/XCode related
-**/ios/**/*.mode1v3
-**/ios/**/*.mode2v3
-**/ios/**/*.moved-aside
-**/ios/**/*.pbxuser
-**/ios/**/*.perspectivev3
-**/ios/**/*sync/
-**/ios/**/.sconsign.dblite
-**/ios/**/.tags*
-**/ios/**/.vagrant/
-**/ios/**/DerivedData/
-**/ios/**/Icon?
-**/ios/**/Pods/
-**/ios/**/.symlinks/
-**/ios/**/profile
-**/ios/**/xcuserdata
-**/ios/.generated/
-**/ios/Flutter/App.framework
-**/ios/Flutter/Flutter.framework
-**/ios/Flutter/Generated.xcconfig
-**/ios/Flutter/app.flx
-**/ios/Flutter/app.zip
-**/ios/Flutter/flutter_assets/
-**/ios/Flutter/flutter_export_environment.sh
-**/ios/ServiceDefinitions.json
-**/ios/Runner/GeneratedPluginRegistrant.*
-
-# Exceptions to above rules.
-!**/ios/**/default.mode1v3
-!**/ios/**/default.mode2v3
-!**/ios/**/default.pbxuser
-!**/ios/**/default.perspectivev3
-!/packages/flutter_tools/test/data/dart_dependencies_test/**/.packages

android/.gitignore

@@ -0,0 +1,8 @@
+gradle-wrapper.jar
+/.gradle
+/gradle
+/captures/
+/gradlew
+/gradlew.bat
+/local.properties
+GeneratedPluginRegistrant.java

android/app/build.gradle

@@ -37,13 +37,12 @@ android {
     }
 
     defaultConfig {
-        // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
         applicationId "de.johrpan.musicus"
         minSdkVersion 16
         targetSdkVersion 28
         versionCode flutterVersionCode.toInteger()
         versionName flutterVersionName
-        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
+        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
     }
 
     buildTypes {
@@ -62,6 +61,6 @@ flutter {
 dependencies {
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
     testImplementation 'junit:junit:4.12'
-    androidTestImplementation 'com.android.support.test:runner:1.0.2'
-    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
+    androidTestImplementation 'androidx.test:runner:1.1.1'
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.1'
 }

android/app/src/main/AndroidManifest.xml

@@ -11,18 +11,18 @@
             android:name=".MainActivity"
             android:launchMode="singleTop"
             android:theme="@style/LaunchTheme"
-            android:configChanges="orientation|keyboardHidden|keyboard|screenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
+            android:configChanges="orientation|keyboardHidden|keyboard|screenSize|smallestScreenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
             android:hardwareAccelerated="true"
             android:windowSoftInputMode="adjustResize">
 
-            <meta-data
-                android:name="io.flutter.app.android.SplashScreenUntilFirstFrame"
-                android:value="true" />
-
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
+
+        <meta-data
+            android:name="flutterEmbedding"
+            android:value="2" />
     </application>
 </manifest>

android/app/src/main/kotlin/de/johrpan/musicus/MainActivity.kt

@@ -1,13 +1,12 @@
 package de.johrpan.musicus
 
-import android.os.Bundle
-
-import io.flutter.app.FlutterActivity
+import androidx.annotation.NonNull;
+import io.flutter.embedding.android.FlutterActivity
+import io.flutter.embedding.engine.FlutterEngine
 import io.flutter.plugins.GeneratedPluginRegistrant
 
 class MainActivity: FlutterActivity() {
-  override fun onCreate(savedInstanceState: Bundle?) {
-    super.onCreate(savedInstanceState)
-    GeneratedPluginRegistrant.registerWith(this)
+    override fun configureFlutterEngine(@NonNull flutterEngine: FlutterEngine) {
+        GeneratedPluginRegistrant.registerWith(flutterEngine);
     }
 }

android/build.gradle

@@ -1,12 +1,12 @@
 buildscript {
-    ext.kotlin_version = '1.2.71'
+    ext.kotlin_version = '1.3.50'
     repositories {
         google()
         jcenter()
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.2.1'
+        classpath 'com.android.tools.build:gradle:3.5.0'
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
     }
 }

android/gradle.properties

@@ -0,0 +1,4 @@
+org.gradle.jvmargs=-Xmx1536M
+android.enableR8=true
+android.useAndroidX=true
+android.enableJetifier=true