Use map_file_generator only for the supported file systems

map_file_generator can generate map files from erofs and ext# file
systems. Check the file system type and copy images and generate map
files if supported. Otherwise skip these steps.
If the image files are not copied, add_img_to_target_files will
generate the image files and map files.

Bug: 286870582
Test: lunch bertha_x86_64-userdebug && m dist
Change-Id: Ib92dd989cf61b1e376107a507eae9222ceb1d0d4