Change TARGET_BUILD_APPS_WITH_BUILD_NUMBER to a product variable

This change allows unbundled app builds to embed the build number in the
version name by defining PRODUCT_BUILD_APPS_WITH_BUILD_NUMBER, so that
APK files from a build can be easily identified.

Ignore-AOSP-First: changes in topics with internal-only projects
Test: manual build
Bug: 340311907
Change-Id: If7feda5eec2bc1e54a90b4adae1bd6da19e3ea45
diff --git a/core/product.mk b/core/product.mk
index 7908e1d..d469c0e 100644
--- a/core/product.mk
+++ b/core/product.mk
@@ -493,6 +493,9 @@
 # by this flag.
 _product_single_value_vars += PRODUCT_NOT_DEBUGGABLE_IN_USERDEBUG
 
+# If set, the default value of the versionName of apps will include the build number.
+_product_single_value_vars += PRODUCT_BUILD_APPS_WITH_BUILD_NUMBER
+
 .KATI_READONLY := _product_single_value_vars _product_list_vars
 _product_var_list :=$= $(_product_single_value_vars) $(_product_list_vars)