Add soong_only_diff_test target

soong_only_diff_test will build a zip file of all the make partitions,
and one of all the soong-built partitions, and diff them.

Right now the zips have some diffs and the test fails, this is
just the initial implementation.

Bug: 376539388
Test: m soong_only_diff_test
Change-Id: Ief5bf36d1662258f7444607ee0c93114fcdce3be