omni: change branch refs to 13.0

Change-Id: I07996ea076918aae2868a3e8c82d3920d9ab5b0f
diff --git a/config/version.mk b/config/version.mk
index 9bc9ff7..edd71f6 100644
--- a/config/version.mk
+++ b/config/version.mk
@@ -24,7 +24,7 @@
     ROM_VERSION := $(PLATFORM_VERSION)-$(shell date +%Y%m%d)-$(TARGET_PRODUCT_SHORT)-$(ROM_BUILDTYPE)
 endif
 
-ROM_BRANCH := android-12.1
+ROM_BRANCH := android-13.0
 
 # Apply it to build.prop
 PRODUCT_PRODUCT_PROPERTIES += \