lineage: Isolate LineageOS versions properties for build.prop

 * Our properties were supposed to go to /system/etc/prop.default
    after the following commit:
    "lineage: Move to Google's method of defining system default props"
    Change-Id: I6cb0e28a7599b010b389cc541015a37010a00f4b

 * However if BOARD_PROPERTY_OVERRIDES_SPLIT_ENABLED is not true,
    only /default.prop will retain the properties contents of
    ADDITIONAL_DEFAULT_PROPERTIES and PRODUCT_SYSTEM_DEFAULT_PROPERTIES,
    and none of our versioning identification was held in the system

 * Enabling BOARD_PROPERTY_OVERRIDES_SPLIT_ENABLED globally would
    break all properties on devices that handle partitions usually
    at the device level rather than the kernel due to mounting races

 * Create a new main_version.mk file to isolate LineageOS properties
    that define the system's versions identifications, and use the
    ADDITIONAL_BUILD_PROPERTIES internal build variable to include
    from build/make through a common vendor main.mk entrypoint

Change-Id: I0060141c097b3d14c3710eee1e0caf7110634967
Signed-off-by: Adrian DC <radian.dc@gmail.com>
diff --git a/config/main_version.mk b/config/main_version.mk
new file mode 100644
index 0000000..96213b0
--- /dev/null
+++ b/config/main_version.mk
@@ -0,0 +1,19 @@
+# LineageOS System Version
+ADDITIONAL_BUILD_PROPERTIES += \
+    ro.lineage.version=$(LINEAGE_VERSION) \
+    ro.lineage.releasetype=$(LINEAGE_BUILDTYPE) \
+    ro.lineage.build.version=$(PRODUCT_VERSION_MAJOR).$(PRODUCT_VERSION_MINOR) \
+    ro.modversion=$(LINEAGE_VERSION) \
+    ro.lineagelegal.url=https://lineageos.org/legal
+
+# LineageOS Platform Display Version
+ADDITIONAL_BUILD_PROPERTIES += \
+    ro.lineage.display.version=$(LINEAGE_DISPLAY_VERSION)
+
+# LineageOS Platform SDK Version
+ADDITIONAL_BUILD_PROPERTIES += \
+    ro.lineage.build.version.plat.sdk=$(LINEAGE_PLATFORM_SDK_VERSION)
+
+# LineageOS Platform Internal Version
+ADDITIONAL_BUILD_PROPERTIES += \
+    ro.lineage.build.version.plat.rev=$(LINEAGE_PLATFORM_REV)