@Override
        public void onClick(View v) {
            if (!mIsCamera) {
                mIsCamera = true;
                startCamera(getActivity(), BoxingBottomSheetFragment.this, BoxingFileHelper.DEFAULT_SUB_DIR);
            }
        }
the most easy to implement {@link PickerContract.View} to show medias with google's Bottom Sheet </br>
for simplest purpose, it only support SINGLE_IMG and VIDEO Mode.
for MULTI_IMG mode, use {@link BoxingViewFragment} instead.

@author ChenSL
boxing-impl/src/main/java/com/bilibili/boxing_impl/ui/BoxingBottomSheetFragment.java