Update bazel to 4.1.0

Changes from 4.0.0 are noted here:
https://github.com/bazelbuild/bazel/releases/tag/4.1.0

Change-Id: I390cfb1d1903ed5f98903d4e17134aa2892eb324
diff --git a/tools/bazel b/tools/bazel
index 4054da3..ef6372b 100755
--- a/tools/bazel
+++ b/tools/bazel
@@ -24,7 +24,7 @@
   exec "${BAZEL_OVERRIDE}" "$@"
 fi
 
-readonly VERSION="4.0.0"
+readonly VERSION="4.1.0"
 
 readonly DOWNLOAD_DIR="${HOME}/.cache/bazel"
 # Directory to unpack bazel into.  This must change whenever bazel changes.