abi: build_abi.sh: compare against predefined ABI

If ABI_DEFINITION is set (usually via build.config), run an actual
analysis with build/abi/diff_abi and create a report for any detected
differences. Also return the tools error code as error code of
build_abi.sh.

Signed-off-by: Matthias Maennich <maennich@google.com>
Change-Id: Ie744290bfd89c455d6ee966f1e5ede41050e7648
1 file changed