(bug 49351) Fix Labs and Tool Labs favicons

Adding favicons for the two projects into /docroot/bits/favicon
since that's the place where we keep favicons for all projects.

I haven't been able to figure out where you guys are keeping
configuration files for labs (neither was mutante), so I'll
just let you point them to here at your convenience.

Bug: 49351, 49352
Change-Id: If2205416f3a7e549e081d7db4f797c4edf1224e4