Define step-0 for vintf finalization

Define `vintf` state that have completed vintf finalization only.
Only if FINAL_STATE is 'unfinalized' run the vintf finalization
process to finalize vintf.
The new step-0 only runs the vintf finalization.

Ignore-AOSP-First: trunk-stable changes (b/304316873)

Bug: 318883690
Test: build-step-0.sh && build/soong/soong_ui.bash \
    --make-mode TARGET_PRODUCT=cf_x86_64_phone TARGET_RELEASE=fina_0 \
    TARGET_BUILD_VARIANT=userdebug droid dist
Change-Id: If3525f38204fa546744b9ccf8dc9e63711823abd
diff --git a/tools/finalization/build-step-1.sh b/tools/finalization/build-step-1.sh
index 88d75fa..7294698 100755
--- a/tools/finalization/build-step-1.sh
+++ b/tools/finalization/build-step-1.sh
@@ -7,8 +7,12 @@
     source $top/build/make/tools/finalization/environment.sh
 
     if [ "$FINAL_STATE" = "unfinalized" ] ; then
-        # Build finalization artifacts.
+        # VINTF finalization
         source $top/build/make/tools/finalization/finalize-vintf-resources.sh
+    fi;
+
+    if [ "$FINAL_STATE" = "unfinalized" ] || [ "$FINAL_STATE" = "vintf" ] ; then
+        # Build finalization artifacts.
         source $top/build/make/tools/finalization/finalize-sdk-resources.sh
     fi;
 }