Merge branch 'stable-3.0' into stable-3.1

* stable-3.0:
  Bump Bazel version to 3.7.0
  Upgrade bazlets to latest stable-3.0 to build with 3.0.13 API

Change-Id: Ic22b87001e4e4ca2d02f0807d8db2c4cc489c306

.bazelversion

diff --git a/.bazelversion b/.bazelversion
index 1545d96..7c69a55 100644
--- a/.bazelversion
+++ b/.bazelversion
@@ -1 +1 @@
-3.5.0
+3.7.0