sm6225-common: Declare shipping api level

Change-Id: I1d5c5599d65aca93b1c32bfef4ada3ccb8145d6c
diff --git a/common.mk b/common.mk
index 5ecbbad..bd47c49 100644
--- a/common.mk
+++ b/common.mk
@@ -16,3 +16,6 @@
 
 # Inherit the proprietary files
 $(call inherit-product, vendor/xiaomi/sm6225-common/sm6225-common-vendor.mk)
+
+# Shipping API Level
+PRODUCT_SHIPPING_API_LEVEL := 33