Define non-system module as variable

Define non_system_module in base_rules.mk when the module is product, vendor,
product_services or proprietary module.

Bug: 74699609

Test: m -j
Change-Id: Iebdd3ec8c643be3d9877b7a96cbdd83465fa3878
diff --git a/core/clear_vars.mk b/core/clear_vars.mk
index b47071a..f9e07f8 100644
--- a/core/clear_vars.mk
+++ b/core/clear_vars.mk
@@ -494,6 +494,7 @@
 LOCAL_IS_AUX_MODULE :=
 
 full_android_manifest :=
+non_system_module :=
 
 # Trim MAKEFILE_LIST so that $(call my-dir) doesn't need to
 # iterate over thousands of entries every time.