Generate lsdump without sdump

This commit changes <dump-files> to be an optional parameter for
header-abi-linker. The linker can generate lsdump files for libraries
without source files.

Test: ./test.py
Test: ./create_reference_dumps.py -products aosp_arm64
Bug: 135728451
Change-Id: Ib9fe56591bd476921904118b1bafcdf2e987f8bb
4 files changed