update android gradle configuration and declare activity in library

If you declare the activity in the library, the hosting application's
manifest will get merged with the library manifest and then the end user
doesn't have to edit their manifest before this plugin works.

also updated to latest gradle plugin and kotlin versions

android/build.gradle

@@ -10,8 +10,8 @@ buildscript {
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.3'
-        classpath 'org.jetbrains.kotlin:kotlin-gradle-plugin:1.1.2-4'
+        classpath 'com.android.tools.build:gradle:3.1.4'
+        classpath 'org.jetbrains.kotlin:kotlin-gradle-plugin:1.2.51'
     }
 }
 
@@ -28,7 +28,7 @@ apply plugin: 'com.android.library'
 apply plugin: 'kotlin-android'
 
 android {
-    compileSdkVersion 27
+    compileSdkVersion 28
     buildToolsVersion '27.0.3'
 
     sourceSets {
@@ -36,7 +36,7 @@ android {
     }
     defaultConfig {
         minSdkVersion 16
-        targetSdkVersion 25
+        targetSdkVersion 28
         versionCode 1
         versionName "1.0"
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
@@ -47,7 +47,7 @@ android {
 }
 
 dependencies {
-    implementation 'org.jetbrains.kotlin:kotlin-stdlib-jre7:1.1.2-4'
+    implementation 'org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.2.51'
     implementation 'me.dm7.barcodescanner:zxing:1.9.8'
     implementation 'com.android.support:design:27.1.1'
 }

android/src/main/AndroidManifest.xml

@@ -1,3 +1,7 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
   package="com.yourcompany.barcodescan">
+
+  <application>
+    <activity android:name="com.apptreesoftware.barcodescan.BarcodeScannerActivity" />
+  </application>
 </manifest>

example/android/app/build.gradle

@@ -16,8 +16,8 @@ apply plugin: 'kotlin-android'
 apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"
 
 android {
-    compileSdkVersion 25
-    buildToolsVersion '25.0.3'
+    compileSdkVersion 28
+    buildToolsVersion "27.0.3"
 
     sourceSets {
         main.java.srcDirs += 'src/main/kotlin'
@@ -31,7 +31,7 @@ android {
         // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
         applicationId "com.yourcompany.barcodescanexample"
         minSdkVersion 16
-        targetSdkVersion 25
+        targetSdkVersion 28
         versionCode 1
         versionName "1.0"
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
@@ -51,5 +51,5 @@ flutter {
 }
 
 dependencies {
-    compile 'org.jetbrains.kotlin:kotlin-stdlib-jre7:1.1.2-4'
+    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
 }

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

@@ -35,6 +35,5 @@
                 <category android:name="android.intent.category.LAUNCHER"/>
             </intent-filter>
         </activity>
-        <activity android:name="com.apptreesoftware.barcodescan.BarcodeScannerActivity"/>
     </application>
 </manifest>

example/android/build.gradle

@@ -1,22 +1,22 @@
 buildscript {
+    ext.kotlin_version = '1.2.41'
     repositories {
+        google()
         jcenter()
-        maven {
-            url "https://maven.google.com"
-        }
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.3'
-        classpath 'org.jetbrains.kotlin:kotlin-gradle-plugin:1.1.2-4'
+        classpath 'com.android.tools.build:gradle:3.1.4'
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
     }
 }
 
 allprojects {
     repositories {
+        google()
         jcenter()
         maven {
-            url "https://maven.google.com"
+            url "https://maven.google.com" // Google's Maven repository
         }
     }
 }
@@ -24,6 +24,8 @@ allprojects {
 rootProject.buildDir = '../build'
 subprojects {
     project.buildDir = "${rootProject.buildDir}/${project.name}"
+}
+subprojects {
     project.evaluationDependsOn(':app')
 }
 

example/android/gradle/wrapper/gradle-wrapper.properties

@@ -3,4 +3,4 @@ distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-3.3-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.4-all.zip

example/ios/Flutter/Debug.xcconfig

@@ -1 +1,2 @@
+#include "Pods/Target Support Files/Pods-Runner/Pods-Runner.debug.xcconfig"
 #include "Generated.xcconfig"

example/ios/Flutter/Release.xcconfig

@@ -1 +1,2 @@
+#include "Pods/Target Support Files/Pods-Runner/Pods-Runner.release.xcconfig"
 #include "Generated.xcconfig"