build.sh: Fix bug in build script for RC release
build.sh: Fix bug in build script for RC release

For release candidate, the APT repo distribution should be "testing" instead of "stable"

Closes #10346.

PiperOrigin-RevId: 283327228

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