Macro Expansion function is used in 'CustomAnimationPreset.cxx'
& 'TransitionPreset.cxx' to avoid code redundancy.Also appropriate
changes are to made to 'getExpandedFilePath' function.

Change-Id: I6b6ae068db3499fe2de2e78a884f9e0737577651
Reviewed-on: https://gerrit.libreoffice.org/5910Reviewed-by: Thorsten Behrens <thb@documentfoundation.org>
Tested-by: Thorsten Behrens <thb@documentfoundation.org>