Import module-lib and system-server api files too

The change I97ebd1b3ef6aa96d6a9a52a46ce86cfb91df4451 only added support
for grabbing the stub jar files. Grab the api files too.

Bug: 149293194
Test: ./update_prebuilts.py -f 30 <bid>
Change-Id: Ie2ee6d40fcbc5dc8f6041c62d3c227742cce3297
1 file changed