LPS-40570 Change checkDefaultLayoutSetBranches() to public
LPS-40570 Create layout revision after we copied the layouts back to the staging group. We need to delete the layout set branch because we had to add an empty one in the calling process so when the request returns we can properly render the UI.
LPS-40570 Moving new code to method - no logic changes
LPS-40570 sourceGroupId is used before privateLayout in LayoutLocalServiceUtil.exportLayoutsAsFile(
LPS-40570 SF