Organize product vars for adding properties

Properties for <partition>/build.prop are now added via
PRODUCT_<PARTITION>_PROPERTIES.

PRODUCT_SYSTEM_PROPERTIES is added. PRODUCT_SYSTEM_DEFAULT_PROPERTIES
will be deprecated.

PRODUCT_VENDOR_PROPERTIES is added. PRODUCT_PROPERTY_OVERRIDES and
PRODUCT_DEFAULT_PROPERTY_OVERRIDES will be deprecated in favor of the new
variable.

For other partitions (odm, system_ext, product), there is no change.

Exempt-From-Owner-Approval: cherry-pick from internal master

Bug: 117892318
Test: m
Merged-In: I98f3b5d0da661b3ad75260a23754e655103b7a44
(cherry picked from commit ad810b6dae)
Change-Id: I98f3b5d0da661b3ad75260a23754e655103b7a44

core/sysprop.mk

@@ -280,6 +280,10 @@ _prop_files_ := \
 # TODO(b/117892318): don't allow duplicates so that the ordering doesn't matter
 _prop_vars_ := \
     ADDITIONAL_SYSTEM_PROPERTIES \
+    PRODUCT_SYSTEM_PROPERTIES
+
+# TODO(b/117892318): deprecate this
+_prop_vars_ += \
     PRODUCT_SYSTEM_DEFAULT_PROPERTIES
 
 ifndef property_overrides_split_enabled
@@ -316,6 +320,11 @@ ifdef property_overrides_split_enabled
 # TODO(b/117892318): don't allow duplicates so that the ordering doesn't matter
 _prop_vars_ := \
     ADDITIONAL_VENDOR_PROPERTIES \
+    PRODUCT_VENDOR_PROPERTIES
+
+# TODO(b/117892318): deprecate this
+_prop_vars_ += \
+    PRODUCT_DEFAULT_PROPERTY_OVERRIDES \
     PRODUCT_PROPERTY_OVERRIDES
 else
 _prop_vars_ :=