setHeader
Sets a custom header view for the selected app picker.
This method removes any existing header view and adds the provided view to the selectedViewHeader FrameLayout. If the provided view is null, the header will be cleared.
After setting the header, refreshSelectedAppPickerView(false) is called to update the layout based on the presence and size of the new header.
Parameters
view
The custom View to set as the header. Can be null to remove the header.