Updating the BUILD_ID to OC for oc-dev branch.

Bug: None
Test: Build and flashed AIO device
Change-Id: I0c87c33b8fb6cbaf71cdb90ce86097bfb31f4137
Merged-In: I53047dbc0b89c2b3afe5d2af3c0532968f60b893
diff --git a/core/build_id.mk b/core/build_id.mk
index 0e8e2cf..0690c04 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.
 
-export BUILD_ID=MASTER
+export BUILD_ID=OC