Back in 10fb206 when this for loop was added, we didn't have the
subprojects list. That was added in 9bd7bab, but I failed to update one
reference to rootProject. So all has had an evaluation dependency on all
projects, even though it only needs a subset.
This should have little impact, but would prevent weird scenarios like
an issue in :grpc-gae-interop-testing-jdk8 preventing :all-all from
being loaded. Not to say things wouldn't still fail to load, but that
this bug could distract from the real problem. I noticed this
during #8049.
8a9aa41416