[ECO-5020] fix: update AGP plugin

- updated AGP plugin to 8.0
- added build config feature
- added support for older AGP versions

android/build.gradle

@@ -8,7 +8,7 @@ buildscript {
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:7.2.0'
+        classpath 'com.android.tools.build:gradle:8.0.0'
     }
 }
 
@@ -35,6 +35,11 @@ dependencies {
 android {
     compileSdkVersion 32
 
+    // Conditional for compatibility with AGP <4.2.
+    if (project.android.hasProperty("namespace")) {
+        namespace 'io.ably.flutter.plugin'
+    }
+
     // Require Java language level 8 so we can use Method References (used with Lambdas)
     compileOptions {
         sourceCompatibility JavaVersion.VERSION_1_8
@@ -56,6 +61,9 @@ android {
     lintOptions {
         disable 'InvalidPackage'
     }
+    buildFeatures {
+        buildConfig true
+    }
 }
 
 apply from: file("./ably-agent.gradle")

example/android/build.gradle

@@ -1,6 +1,4 @@
 buildscript {
-    ext.kotlin_version = '1.5.31'
-
     repositories {
         google()
         mavenCentral()
@@ -9,7 +7,6 @@ buildscript {
     dependencies {
         classpath 'com.android.tools.build:gradle:7.2.0'
         classpath 'com.google.gms:google-services:4.3.10'
-        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
     }
 }
 

test_integration/android/app/build.gradle

@@ -22,16 +22,11 @@ if (flutterVersionName == null) {
 }
 
 apply plugin: 'com.android.application'
-apply plugin: 'kotlin-android'
 apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"
 
 android {
     compileSdkVersion 32
 
-    sourceSets {
-        main.java.srcDirs += 'src/main/kotlin'
-    }
-
     lintOptions {
         disable 'InvalidPackage'
     }
@@ -57,7 +52,3 @@ android {
 flutter {
     source '../..'
 }
-
-dependencies {
-    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
-}

test_integration/android/build.gradle

@@ -1,14 +1,11 @@
 buildscript {
-    ext.kotlin_version = '1.5.31'
-
     repositories {
         google()
         mavenCentral()
     }
 
     dependencies {
         classpath 'com.android.tools.build:gradle:7.2.0'
-        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
     }
 }