Adding a protected-scope getter for the DistCpOptions, so that a subclass does
not need to save its own copy of the inputOptions supplied to its constructor,
if it wishes to override the createInputFileListing method with logic similar
to the original implementation, i.e. calling CopyListing#buildListing with a path and input options.
Author: Andrew Olson
(cherry picked from commit c15b3bca86a0f973ccdddd020f3ff2d5767ff1bd)
55603529d0