Bump Bazel version to 3.4.1

Change-Id: I6e4830d9efb1ab1a7a41958eda161ce6e85d85d5
diff --git a/.bazelversion b/.bazelversion
index fd2a018..47b322c 100644
--- a/.bazelversion
+++ b/.bazelversion
@@ -1 +1 @@
-3.1.0
+3.4.1