@Override
    public void onBackPressed() {
        if (hideBottomSheet()) {
            return;
        }
        super.onBackPressed();
    }
Default UI Activity for simplest usage, containing layout achieve {@link BottomSheetBehavior}.
Only support SINGLE_IMG and VIDEO Mode.

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