android Google Play Warning: SSL Error Handler Vulnerability

the solution is to remove onReceivedSslError.

To properly handle SSL certificate validation, change your code to invoke SslErrorHandler.proceed() whenever the certificate presented by the server meets your expectations, and invoke SslErrorHandler.cancel() otherwise.

For example, I add an alert dialog to make user have confirmed and seems Google no longer shows warning.

    @Override
    public void onReceivedSslError(WebView view, final SslErrorHandler handler, SslError error) {
    final AlertDialog.Builder builder = new AlertDialog.Builder(this);
    String message = "SSL Certificate error.";
        switch (error.getPrimaryError()) {
            case SslError.SSL_UNTRUSTED:
                message = "The certificate authority is not trusted.";
                break;
            case SslError.SSL_EXPIRED:
                message = "The certificate has expired.";
                break;
            case SslError.SSL_IDMISMATCH:
                message = "The certificate Hostname mismatch.";
                break;
            case SslError.SSL_NOTYETVALID:
                message = "The certificate is not yet valid.";
                break;
        }
        message += " Do you want to continue anyway?";

        builder.setTitle("SSL Certificate Error");
        builder.setMessage(message);
    builder.setPositiveButton("continue", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            handler.proceed();
        }
    });
    builder.setNegativeButton("cancel", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            handler.cancel();
        }
    });
    final AlertDialog dialog = builder.create();
    dialog.show();
}

After this changes it will not show warning. Reference

I was using backendless library old version compile 'com.backendless:backendless:3.0.11' so i update to latest version compile 'com.backendless:backendless:3.0.24' and issue solved.