git.bzl: also clone branches with --depth=1
git.bzl: also clone branches with --depth=1

Cloning branches as added after the fact to the skylark git rules,
once recording the actual commit was implemented. Still support shallow
cloning also when following branches.

Change-Id: Ib7a84de4ada69152e9e7c27e9d84cff39cfd3582
PiperOrigin-RevId: 207866303

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