Write the missing system build props to recovery build prop file.

This was missed by [1], which changed the rules for writing recovery
build prop file.

[1] commit 139c7270361a421592705836391ebb48dafaba57

Bug: 110380063
Bug: 112247573
Test: `m bootimage` with aosp_marlin-userdebug. Check the generated
      recovery build prop file against the one before [1].
Change-Id: Ib5829b01a63eee8e8a09486dd68063ba297b7443
diff --git a/core/Makefile b/core/Makefile
index 2820a71..1657f71 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -1465,6 +1465,7 @@
 $(INSTALLED_RECOVERY_BUILD_PROP_TARGET): \
 		$(INSTALLED_DEFAULT_PROP_TARGET) \
 		$(INSTALLED_VENDOR_DEFAULT_PROP_TARGET) \
+		$(intermediate_system_build_prop) \
 		$(INSTALLED_VENDOR_BUILD_PROP_TARGET) \
 		$(INSTALLED_PRODUCT_BUILD_PROP_TARGET) \
 		$(INSTALLED_PRODUCT_SERVICES_BUILD_PROP_TARGET)
@@ -1473,6 +1474,7 @@
 	$(hide) rm -f $@
 	$(hide) cat $(INSTALLED_DEFAULT_PROP_TARGET) > $@
 	$(hide) cat $(INSTALLED_VENDOR_DEFAULT_PROP_TARGET) >> $@
+	$(hide) cat $(intermediate_system_build_prop) >> $@
 	$(hide) cat $(INSTALLED_VENDOR_BUILD_PROP_TARGET) >> $@
 	$(hide) cat $(INSTALLED_PRODUCT_BUILD_PROP_TARGET) >> $@
 	$(hide) cat $(INSTALLED_PRODUCT_SERVICES_BUILD_PROP_TARGET) >> $@