Remove unused 3p tool missing license terms.

The five-year-old version of owasp sanitizer used to sanitize html in
emails included an old version of findbugs referenced from an unused
Makefile. Since this may have missing license terms and is unused,
deleting makes sense.

Bug: 136097319

Test: packages/apps/Email/tests packages/apps/UnifiedEmail/tests pass.

Change-Id: Id4388a10f59826e5b3fb7f830b30668388dda7be
164 files changed