Allow G1 in tools/jdk/BUILD.java_tools.
Allow G1 in tools/jdk/BUILD.java_tools.

This is a followup to 01e6e05a35633df92cafc20b28eac15cd1aefa09. (I think BUILD.java_tools was introduced in between the creation of the PR for 01e6e05a35633df92cafc20b28eac15cd1aefa09 and its landing.)

Closes #8964.

PiperOrigin-RevId: 259695109

cushon/bazel,katre/bazel,aehlig/bazel,werkt/bazel,dslomov/bazel-windows,davidzchen/bazel,ulfjack/bazel,akira-baruah/bazel,ulfjack/bazel,katre/bazel,akira-baruah/bazel,aehlig/bazel,ButterflyNetwork/bazel,ulfjack/bazel,bazelbuild/bazel,aehlig/bazel,werkt/bazel,safarmer/bazel,perezd/bazel,perezd/bazel,cushon/bazel,aehlig/bazel,werkt/bazel,ulfjack/bazel,meteorcloudy/bazel,meteorcloudy/bazel,ButterflyNetwork/bazel,katre/bazel,bazelbuild/bazel,aehlig/bazel,ulfjack/bazel,akira-baruah/bazel,akira-baruah/bazel,perezd/bazel,ButterflyNetwork/bazel,twitter-forks/bazel,twitter-forks/bazel,katre/bazel,werkt/bazel,ulfjack/bazel,bazelbuild/bazel,safarmer/bazel,meteorcloudy/bazel,ButterflyNetwork/bazel,akira-baruah/bazel,dslomov/bazel,davidzchen/bazel,davidzchen/bazel,perezd/bazel,davidzchen/bazel,meteorcloudy/bazel,safarmer/bazel,bazelbuild/bazel,werkt/bazel,twitter-forks/bazel,safarmer/bazel,dslomov/bazel,dslomov/bazel,dslomov/bazel-windows,perezd/bazel,katre/bazel,meteorcloudy/bazel,davidzchen/bazel,twitter-forks/bazel,perezd/bazel,cushon/bazel,twitter-forks/bazel,ulfjack/bazel,davidzchen/bazel,davidzchen/bazel,cushon/bazel,aehlig/bazel,safarmer/bazel,dslomov/bazel,twitter-forks/bazel,cushon/bazel,dslomov/bazel,bazelbuild/bazel,katre/bazel,aehlig/bazel,perezd/bazel,akira-baruah/bazel,ButterflyNetwork/bazel,bazelbuild/bazel,dslomov/bazel-windows,dslomov/bazel-windows,cushon/bazel,dslomov/bazel,ButterflyNetwork/bazel,meteorcloudy/bazel,werkt/bazel,twitter-forks/bazel,dslomov/bazel-windows,safarmer/bazel,dslomov/bazel-windows,dslomov/bazel,meteorcloudy/bazel