Version bump to SD1A.210817.015.A3 [core/build_id.mk]

Change-Id: Ie0e5729c3fec59d96346c619f001763cc4b08c93
diff --git a/core/build_id.mk b/core/build_id.mk
index 4e2f597..c5ae2ef 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=SD1A.210817.015.A2
+BUILD_ID=SD1A.210817.015.A3