title: Library migration to AndroidX
body: <p>I'm using Paho MQTT library in my AndroidX application. I'm getting exception <code>NoClassDefFoundError</code> for <code>Landroid/support/v4/content/LocalBroadcastManager</code>. I found that library uses depricated import:</p>
  
  <pre><code>import android.support.v4.content.LocalBroadcastManager;
  </code></pre>
  
  <p>Function that rises exception:</p>
  
  <pre><code>private void registerReceiver(BroadcastReceiver receiver) {
      IntentFilter filter = new IntentFilter();
              filter.addAction(MqttServiceConstants.CALLBACK_TO_ACTIVITY);
              LocalBroadcastManager.getInstance(myContext).registerReceiver(receiver, filter);
              receiverRegistered = true;
  }
  </code></pre>
  
  <p>How to solve this problem? Should I download source and recompile library? Why it is not already done in latest release?</p>
  
  <p>Whole exception:</p>
  
  <pre><code>E/AndroidRuntime: FATAL EXCEPTION: main
      Process: com.eurbon.pahomqttclientexample, PID: 17368
      java.lang.NoClassDefFoundError: Failed resolution of: Landroid/support/v4/content/LocalBroadcastManager;
          at org.eclipse.paho.android.service.MqttAndroidClient.registerReceiver(MqttAndroidClient.java:450)
          at org.eclipse.paho.android.service.MqttAndroidClient.connect(MqttAndroidClient.java:428)
          at org.eclipse.paho.android.service.MqttAndroidClient.connect(MqttAndroidClient.java:334)
          at paho.android.mqtt_example.MainActivity.MqttConnect(MainActivity.java:121)
          at paho.android.mqtt_example.MainActivity.onCreate(MainActivity.java:63)
          at android.app.Activity.performCreate(Activity.java:6679)
          at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1118)
          at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2618)
          at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2726)
          at android.app.ActivityThread.-wrap12(ActivityThread.java)
          at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1477)
          at android.os.Handler.dispatchMessage(Handler.java:102)
          at android.os.Looper.loop(Looper.java:154)
          at android.app.ActivityThread.main(ActivityThread.java:6119)
          at java.lang.reflect.Method.invoke(Native Method)
          at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
          at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)
       Caused by: java.lang.ClassNotFoundException: Didn't find class "android.support.v4.content.LocalBroadcastManager" on path: DexPathList[[zip file "/data/app/com.eurbon.pahomqttclientexample-1/base.apk"],nativeLibraryDirectories=[/data/app/com.eurbon.pahomqttclientexample-1/lib/x86, /system/lib, /vendor/lib]]
          at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
          at java.lang.ClassLoader.loadClass(ClassLoader.java:380)
          at java.lang.ClassLoader.loadClass(ClassLoader.java:312)
          at org.eclipse.paho.android.service.MqttAndroidClient.registerReceiver(MqttAndroidClient.java:450) 
          at org.eclipse.paho.android.service.MqttAndroidClient.connect(MqttAndroidClient.java:428) 
          at org.eclipse.paho.android.service.MqttAndroidClient.connect(MqttAndroidClient.java:334) 
          at paho.android.mqtt_example.MainActivity.MqttConnect(MainActivity.java:121) 
          at paho.android.mqtt_example.MainActivity.onCreate(MainActivity.java:63) 
          at android.app.Activity.performCreate(Activity.java:6679) 
          at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1118) 
          at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2618) 
          at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2726) 
          at android.app.ActivityThread.-wrap12(ActivityThread.java) 
          at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1477) 
          at android.os.Handler.dispatchMessage(Handler.java:102) 
          at android.os.Looper.loop(Looper.java:154) 
          at android.app.ActivityThread.main(ActivityThread.java:6119) 
          at java.lang.reflect.Method.invoke(Native Method) 
          at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886) 
          at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776) 
  </code></pre>