chore: update android build.gradle

- Remove unused 'org.jetbrains.kotlin.android' plugin
- Remove 'kotlinOptions' block for JVM target compatibility update
- Add exclusion for 'androidsupportmultidexversion.txt' in packagingOptions

feat: add FlutterLogbackAppender for logging in Android

- Add new FlutterLogbackAppender class for logging
- Implement append method to handle log events
- Include mainThreadHandler for posting log data asynchronously
- Provide setChannel method for setting MethodChannel in FlutterLogbackAppender

refactor: simplify channel set in OptimizelyFlutterSdkPlugin.java

- Update channel set method to use static reference directly

Author: muzahidul-opti

android/build.gradle

@@ -1,6 +1,5 @@
 plugins {
     id "com.android.library"
-    id "org.jetbrains.kotlin.android"
 }
 
 group 'com.optimizely.optimizely_flutter_sdk'
@@ -54,10 +53,6 @@ android {
         sourceCompatibility JavaVersion.VERSION_1_8
         targetCompatibility JavaVersion.VERSION_1_8
     }
-
-    kotlinOptions {
-        jvmTarget = "1.8"
-    }
     packagingOptions {
         exclude 'androidsupportmultidexversion.txt'
     }
@@ -73,7 +68,6 @@ dependencies {
     implementation 'com.github.tony19:logback-android:3.0.0'
     implementation 'org.slf4j:slf4j-api:2.0.7'
 
-    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:2.1.0"
     implementation "com.optimizely.ab:android-sdk:5.0.1"
     implementation 'com.fasterxml.jackson.core:jackson-databind:2.17.2'
     implementation ('com.google.guava:guava:19.0') {

android/src/main/java/com/optimizely/optimizely_flutter_sdk/FlutterLogbackAppender.java

@@ -0,0 +1,42 @@
+package com.optimizely.optimizely_flutter_sdk;
+
+import android.os.Handler;
+import android.os.Looper;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import ch.qos.logback.classic.spi.ILoggingEvent;
+import ch.qos.logback.core.AppenderBase;
+import io.flutter.plugin.common.MethodChannel;
+
+public class FlutterLogbackAppender extends AppenderBase<ILoggingEvent> {
+
+    public static final String CHANNEL_NAME = "optimizely_flutter_sdk/logs";
+    public static MethodChannel channel;
+    private static final Handler mainThreadHandler = new Handler(Looper.getMainLooper());
+
+    public static void setChannel(MethodChannel channel) {
+        FlutterLogbackAppender.channel = channel;
+    }
+
+    @Override
+    protected void append(ILoggingEvent event) {
+        if (channel == null) {
+            return;
+        }
+
+        String message = event.getFormattedMessage();
+        int level = event.getLevel().toInt();
+
+        Map<String, Object> logData = new HashMap<>();
+        logData.put("level", level);
+        logData.put("message", message);
+
+        mainThreadHandler.post(() -> {
+            if (channel != null) {
+                channel.invokeMethod("log", logData);
+            }
+        });
+    }
+}

android/src/main/java/com/optimizely/optimizely_flutter_sdk/FlutterLogbackAppender.kt

@@ -191,7 +191,7 @@ public void onDetachedFromEngine(@NonNull FlutterPluginBinding binding) {
     }
 
     // Clean up the channel
-    FlutterLogbackAppender.Companion.setChannel(null);
+    FlutterLogbackAppender.setChannel(null);
   }
 
   @Override