WebView - не открывается FilePicker по нажатию кнопки

        String url = "http://my-site.com";
        WebView myView = (WebView)this.findViewById(R.id.webView1);
        WebSettings settings = myView.getSettings();
        settings.setJavaScriptEnabled(true);
        settings.setJavaScriptCanOpenWindowsAutomatically(true);
        settings.setLoadsImagesAutomatically(true);
        settings.setAllowContentAccess(true);
        settings.setAllowFileAccess(true);
        myView.setWebViewClient(new MyWebViewClient()); //for internal-navigation only
        myView.loadUrl(url);

            // For Lollipop 5.0+ Devices
            @TargetApi(Build.VERSION_CODES.LOLLIPOP)
            public boolean onShowFileChooser(WebView mWebView, ValueCallback<Uri[]> filePathCallback, WebChromeClient.FileChooserParams fileChooserParams)
            {
                if (uploadMessage != null) {
                    uploadMessage.onReceiveValue(null);
                    uploadMessage = null;
                }
 
                uploadMessage = filePathCallback;
 
                Intent intent = fileChooserParams.createIntent();
 
                //little fix for 'type' argument ... because our intent already has prepared type, we need to add option for 'Gallery', and we do it by adding 'image/*'
                // [url]http://stackoverflow.com/questions/13065838/what-are-the-possible-intent-types-for-intent-settypetype[/url]
                intent.setType("image/*,application/pdf,application/vnd.ms-powerpoint,.jpg,.png,.ppt,.pptx*");
 
                try
                {
                    startActivityForResult(intent, REQUEST_SELECT_FILE);
                } catch (ActivityNotFoundException e)
                {
                    uploadMessage = null;
                    Toast.makeText(null, "Cannot Open File Chooser", Toast.LENGTH_LONG).show();
                    return false;
                }
                return true;
            }

intent.setType("image/*,application/pdf,application/vnd.ms-powerpoint,.jpg,.png,.ppt,.pptx*");

                intent.setType("image/*");
                String[] mimetypes = {"application/pdf", "application/vnd.ms-powerpoint", "image/*" };
                intent.putExtra(Intent.EXTRA_MIME_TYPES, mimetypes);