Merge pull request kubernetes#49975 from ixdy/automated-cherry-pick-of-#49833-upstream-release-1.7

Automated cherry pick of kubernetes#49833

Author: wojtek-t

build/root/.bazelrc

@@ -7,3 +7,7 @@ build --workspace_status_command hack/print-workspace-status.sh
 
 # Make /tmp hermetic
 build --sandbox_tmpfs_path=/tmp
+
+# Ensure that Bazel never runs as root, which can cause unit tests to fail.
+# This flag requires Bazel 0.5.0+
+build --sandbox_fake_username