We currently have no tests for the Reindex injector stack, and it is
not uncommon for changes to break Reindex as contributors do not
always know or remember to run it.
Add tests that run the Reindex program directly via GerritLauncher,
using a real injector stack on a newly created site.
Eventually we may want to reindex a site with changes in it, wiring up
GerritServer, which is beyond the scope of this test.
Change-Id: Ic6f32ee4d24395be74b3ea60b9084c79531c6a4a
dc80fddce0