(1/4) Empty APIs for SupplementalApi module.

Soong conditional changes to allow SupplementalApi targets for
internal builds only.

Bug: 208708734
Test: mmm -j packages/modules/SupplementalApi
Change-Id: I51ae41a7533c73d4e6778f436acdef5cb2a3ed15
diff --git a/core/android_soong_config_vars.mk b/core/android_soong_config_vars.mk
index d24449b..718e3e5 100644
--- a/core/android_soong_config_vars.mk
+++ b/core/android_soong_config_vars.mk
@@ -103,3 +103,11 @@
 # TODO(b/196084106): Remove when Java optimizations enabled by default for
 # system packages.
 $(call add_soong_config_var,ANDROID,SYSTEM_OPTIMIZE_JAVA)
+
+# Check for SupplementalApi module.
+ifeq ($(wildcard packages/modules/SupplementalApi),)
+$(call add_soong_config_var_value,ANDROID,include_nonpublic_framework_api,false)
+else
+$(call add_soong_config_var_value,ANDROID,include_nonpublic_framework_api,true)
+endif
+