config: Add new prop for major.minor build version

This only include the major and minor version as returned
by the updater.

Change-Id: I4b203fcddb9ab60958063906c3ed4aa6f0607277

config/common.mk

@@ -313,6 +313,7 @@ endif
 PRODUCT_PROPERTY_OVERRIDES += \
     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