Version 2.9.0-21.2.beta

* Cherry-pick e55aac275ea1e22162fbfd88ed786c9dd4f455f7 to beta
diff --git a/tools/VERSION b/tools/VERSION
index e43d13a..4cf53fd 100644
--- a/tools/VERSION
+++ b/tools/VERSION
@@ -34,6 +34,6 @@
 MINOR 9
 PATCH 0
 PRERELEASE 21
-PRERELEASE_PATCH 1
+PRERELEASE_PATCH 2
 ABI_VERSION 38
 OLDEST_SUPPORTED_ABI_VERSION 38