One option might be to do the tag transformations in the data file before running OsmAndMapCreator.

You can do tag transforms with osmosis:

https://github.com/SomeoneElseOSM/SomeoneElse-style/blob/osmosis/update_render.sh#L203

or with osm-tags-transform:

https://github.com/SomeoneElseOSM/SomeoneElse-style/blob/master/update_render.sh#L203

You can get osm-tags-transform from here:

https://github.com/osmcode/osm-tags-transform

Those example transformations are of names in different languages; obviously you’d want to look at “highway” tags.