Generate product build props always

GSI do not build product partition, and contains the product
contents under /system/product/. Original logic do not generate
the product build props on this case.

The patch fixes the logic for product build props generation to
align the other partitions.

Bug: 157191627
Test: build aosp_arm64-userdebug
Test: check /system/product/build.prop in out folder
Change-Id: I350bbf8c024f747c86c6c54065d690f6b46f30c6
Merged-In: Ia88c8efecb18db9c27baa466e492bfd898b581d3
diff --git a/core/Makefile b/core/Makefile
index d5b3110..4973139 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -587,9 +587,7 @@
 	@echo Target product buildinfo: $@
 	@mkdir -p $(dir $@)
 	$(hide) echo > $@
-ifdef BOARD_USES_PRODUCTIMAGE
 	$(hide) $(call generate-common-build-props,product,$@)
-endif  # BOARD_USES_PRODUCTIMAGE
 	$(hide) $(foreach file,$(product_prop_files), \
 	    if [ -f "$(file)" ]; then \
 	        echo Target product properties from: "$(file)"; \