Android file chooser is not opening from WebView in Lollipop nor Marshmallow

Question

I'm developing an app, that uses a WebView to access some logic. The logic, has a part where the user can upload a picture, but, I can't seem to find a way for the app to do so.
The code I'm using as example is in this link.

As you will see, a custom Intent is set from the WebChromeClient, however, the file chooser does not open at all. Code:

public void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType){  

                // Update message
                mUploadMessage = uploadMsg;

                try{    

                    // Create AndroidExampleFolder at sdcard

                    File imageStorageDir = new File(
                                           Environment.getExternalStoragePublicDirectory(
                                           Environment.DIRECTORY_PICTURES)
                                           , "AndroidExampleFolder");

                    if (!imageStorageDir.exists()) {
                        // Create AndroidExampleFolder at sdcard
                        imageStorageDir.mkdirs();
                    }

                    // Create camera captured image file path and name 
                    File file = new File(
                                    imageStorageDir + File.separator + "IMG_"
                                    + String.valueOf(System.currentTimeMillis()) 
                                    + ".jpg");

                    mCapturedImageURI = Uri.fromFile(file); 

                    // Camera capture image intent
                    final Intent captureIntent = new Intent(
                                                  android.provider.MediaStore.ACTION_IMAGE_CAPTURE);

                    captureIntent.putExtra(MediaStore.EXTRA_OUTPUT, mCapturedImageURI);

                    Intent i = new Intent(Intent.ACTION_GET_CONTENT); 
                    i.addCategory(Intent.CATEGORY_OPENABLE);
                    i.setType("image/*");

                    // Create file chooser intent
                    Intent chooserIntent = Intent.createChooser(i, "Image Chooser");

                    // Set camera intent to file chooser 
                    chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS
                                           , new Parcelable[] { captureIntent });

                    // On select image call onActivityResult method of activity
                    startActivityForResult(chooserIntent, FILECHOOSER_RESULTCODE);

                  }
                 catch(Exception e){
                     Toast.makeText(getBaseContext(), "Exception:"+e, 
                                Toast.LENGTH_LONG).show();
                 }

            }

Thanks in advance!
EDIT

So, after @JoxTraex enlightened me, I realized that the file chooser was not triggering because I was not overriding any methods of the WebChromeClient. Now, the file chooser is prompting, but, if a select an image, the image doesn't get uploaded.
The code I'm using for the file chooser:

@Override
            public boolean onShowFileChooser(WebView webView, ValueCallback<Uri[]> filePathCallback, FileChooserParams fileChooserParams) {
                openFileChooser(filePathCallback, "");
                return super.onShowFileChooser(webView, filePathCallback, fileChooserParams);
            }

            public void openFileChooser(ValueCallback<Uri[]> uploadMsg, String acceptType){
                // Update message
                //mUploadMessage = uploadMsg.this;
                try{
                    // Create AndroidExampleFolder at sdcard
                    File imageStorageDir = new File(
                            Environment.getExternalStoragePublicDirectory(
                                    Environment.DIRECTORY_PICTURES)
                            , "AndroidExampleFolder");

                    if (!imageStorageDir.exists()) {
                        // Create AndroidExampleFolder at sdcard
                        imageStorageDir.mkdirs();
                    }

                    // Create camera captured image file path and name
                    File file = new File(
                            imageStorageDir + File.separator + "IMG_"
                                    + String.valueOf(System.currentTimeMillis())
                                    + ".jpg");

                    mCapturedImageURI = Uri.fromFile(file);

                    // Camera capture image intent
                    final Intent captureIntent = new Intent(
                            android.provider.MediaStore.ACTION_IMAGE_CAPTURE);

                    captureIntent.putExtra(MediaStore.EXTRA_OUTPUT, mCapturedImageURI);

                    Intent i = new Intent(Intent.ACTION_GET_CONTENT);
                    i.addCategory(Intent.CATEGORY_OPENABLE);
                    i.setType("image/*");

                    // Create file chooser intent
                    Intent chooserIntent = Intent.createChooser(i, "Image Chooser");

                    // Set camera intent to file chooser
                    chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS
                            , new Parcelable[] { captureIntent });

                    // On select image call onActivityResult method of activity
                    startActivityForResult(chooserIntent, FILECHOOSER_RESULTCODE);

                }
                catch(Exception e){
                    Toast.makeText(getBaseContext(), "Exception:"+e,
                            Toast.LENGTH_LONG).show();
                }

            }

Thanks in advance!

Answer 1

Well, after struggling with some listeners, I found a code that resolved my situation. Nevertheless, thanks to @JoxTraex and this dude.