Version bump to QD4A.200317.021 [core/build_id.mk]

Change-Id: I30db1d492d16b582e0be59e3ac6f476ddc41b51a
diff --git a/core/build_id.mk b/core/build_id.mk
index 66ed71e..e49ce46 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=QD4A.200317.020
+BUILD_ID=QD4A.200317.021