Version bump to QQ2A.200501.001.B2 [core/build_id.mk]

Change-Id: I474bf28ef86c76dd604fbece203c15a91e7ce92a
diff --git a/core/build_id.mk b/core/build_id.mk
index 4a88b8d..63acb7c 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=QQ2A.200501.001.B1
+BUILD_ID=QQ2A.200501.001.B2