Updating gradle and Android SDK version

android/build.gradle

@@ -8,7 +8,7 @@ buildscript {
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.1.2'
+        classpath 'com.android.tools.build:gradle:3.2.1'
     }
 }
 
@@ -21,8 +21,8 @@ allprojects {
 apply plugin: 'com.android.library'
 
 android {
-    compileSdkVersion 25
-    buildToolsVersion '27.0.3'
+    compileSdkVersion 28
+    buildToolsVersion '28.0.3'
 
     defaultConfig {
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"

example/android/app/build.gradle

@@ -15,8 +15,8 @@ apply plugin: 'com.android.application'
 apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"
 
 android {
-    compileSdkVersion 27
-    buildToolsVersion '27.0.3'
+    compileSdkVersion 28
+    buildToolsVersion '28.0.3'
 
     lintOptions {
         disable 'InvalidPackage'
@@ -27,6 +27,7 @@ android {
         
         // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
         applicationId "com.yourcompany.flutter_webview_plugin_example"
+        minSdkVersion 16
     }
 
     buildTypes {
@@ -43,7 +44,7 @@ flutter {
 }
 
 dependencies {
-    androidTestCompile 'com.android.support:support-annotations:25.0.0'
-    androidTestCompile 'com.android.support.test:runner:0.5'
-    androidTestCompile 'com.android.support.test:rules:0.5'
+    androidTestImplementation 'com.android.support:support-annotations:28.0.0'
+    androidTestImplementation 'com.android.support.test:runner:1.0.2'
+    androidTestImplementation 'com.android.support.test:rules:1.0.2'
 }

example/android/app/src/main/AndroidManifest.xml

@@ -3,8 +3,6 @@
     android:versionCode="1"
     android:versionName="0.0.1">
 
-    <uses-sdk android:minSdkVersion="16" android:targetSdkVersion="21" />
-
     <!-- The INTERNET permission is required for development. Specifically,
          flutter needs it to communicate with the running application
          to allow setting breakpoints, to provide hot reload, etc.

example/android/build.gradle

@@ -8,7 +8,7 @@ buildscript {
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.1.1'
+        classpath 'com.android.tools.build:gradle:3.2.1'
     }
 }