dump_apex_info generates apex-info-list.xml in /apex

Since --root_dir argument tells the root, we can calculate the path to
the generated apex-info-list.xml.

This simplies the invocation of the tool from
Make/check_target_files_vintf.

Bug: n/a
Test: VendorApexHostTestCases
Change-Id: I85dec1141f6889d181d4a4fade4d8bd7ca9ceca9
1 file changed