Bump Bazel version to 3.4.1

Change-Id: Iaca8a67064c0b50d04bdc23a52db869a55635d48
diff --git a/.bazelversion b/.bazelversion
index fd2a018..47b322c 100644
--- a/.bazelversion
+++ b/.bazelversion
@@ -1 +1 @@
-3.1.0
+3.4.1