NFA allows you to import application mappings from CSV files using the racmd -import command.
NFA provides you with several .csv templates for each type of application mappings that are available, ie host, subnet, tos, nbar2. Once you have the csv files configured correctly you can import the files. More details are in the link below:
More details
Import Application Mapping Rules - CA Network Flow Analysis - 9.5.0 - CA Technologies Documentation
I don't think it is currently possible to import them via rest directly from Microsoft at this time.
NFA will be adding some more API support in the next release, 10.0, but not sure that will be an option yet.