Merge "Update go.mod to 1.21" into main am: 9e4744383a am: 9e59d40c2c

Original change: https://android-review.googlesource.com/c/platform/build/+/2874720

Change-Id: Ic556800cda077fe792a89e6272624932b9dbcef5
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
diff --git a/core/build_id.mk b/core/build_id.mk
index bed839f..8a68056 100644
--- a/core/build_id.mk
+++ b/core/build_id.mk
@@ -18,4 +18,4 @@
 # (like "CRB01").  It must be a single word, and is
 # capitalized by convention.
 
-BUILD_ID=MAIN
+BUILD_ID=UDC