public class MainActivity extends AppCompatActivity {

public String secndCaller;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);


}

   //this is the method I need to be called from my AccessibilityService

public void makeCall (){
    Intent callIntent = new Intent(Intent.ACTION_CALL);
    callIntent.setData(Uri.parse("tel:" + 123));
    callIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.CALL_PHONE)
            != PackageManager.PERMISSION_GRANTED) {
        return;
    }
    startActivity(callIntent);
}

public class MyAccessibilityService extends AccessibilityService {


@Override
protected void onServiceConnected() {
    super.onServiceConnected();

    Toast.makeText(this, "Service connected", Toast.LENGTH_SHORT).show();
    AccessibilityServiceInfo info = new AccessibilityServiceInfo();

    info.eventTypes = AccessibilityEvent.TYPE_WINDOW_CONTENT_CHANGED;
    info.packageNames = null;
    info.feedbackType = AccessibilityServiceInfo.FEEDBACK_GENERIC;
    info.flags = AccessibilityServiceInfo.FLAG_INCLUDE_NOT_IMPORTANT_VIEWS;
    info.notificationTimeout = 0;
    this.setServiceInfo(info);
}

@RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN_MR2)
@Override
public void onAccessibilityEvent(AccessibilityEvent event) {

    boolean phone = event.getPackageName().toString().equals("com.android.dialer");

    if (event.getEventType() == AccessibilityEvent.TYPE_WINDOW_CONTENT_CHANGED && phone) {


        AccessibilityNodeInfo info = event.getSource();
        if (info != null) {

            if (info.getText() != null) {
                String duration = info.getText().toString();
                String firstSecond = "00: 01";
                Rect node = new Rect();
                info.getBoundsInScreen(node);
                String node2 = node.toString();

                if (firstSecond.equals(duration) &&
                        info.getContentDescription() == null &&
                        node2.equals("Rect(208, 100 - 272, 132)")) {



                    //Here is where I need the makeCall method to be called                        makeCall();



                }
                } ...