Export PRODUCT_BUILD_PROP_OVERRIDES to soong

Change-Id: I6b6da3ef5b76cec5274f58b9337974d61771cecd
diff --git a/core/soong_extra_config.mk b/core/soong_extra_config.mk
index 00b5c0f..2d0c2d8 100644
--- a/core/soong_extra_config.mk
+++ b/core/soong_extra_config.mk
@@ -44,6 +44,8 @@
 $(call add_json_list, PRODUCT_ODM_PROPERTIES,            $(call collapse-prop-pairs,PRODUCT_ODM_PROPERTIES))
 $(call add_json_list, PRODUCT_PROPERTY_OVERRIDES,        $(call collapse-prop-pairs,PRODUCT_PROPERTY_OVERRIDES))
 
+$(call add_json_list, PRODUCT_BUILD_PROP_OVERRIDES,      $(call collapse-prop-pairs,PRODUCT_BUILD_PROP_OVERRIDES))
+
 $(call add_json_str, BootloaderBoardName, $(TARGET_BOOTLOADER_BOARD_NAME))
 
 $(call add_json_bool, SdkBuild, $(filter sdk sdk_addon,$(MAKECMDGOALS)))