Run diff with golden output

Simply running ./rundiff.sh works. When the changes are found, you can accept the changes by running the following command.

./rundiff.sh --update

How to prepare golden input

testdata/root is pseudo-root dir for linkerconfig.

testdata/root/
    system/etc/
        sanitizer.libraries.txt
        vndkcorevariant.libraries.txt
    system/apex/
        <apex>/
            apex_manifest.json   # copied from intermediate apex_manifest_full.json
            bin/.keep            # indicates to generate ld.config.txt for this apex