Deprecate VNDK based on feature flag

A new feature flag RELEASE_DEPRECATE_VNDK is added to control VNDK
deprecation. Use this value to decide whether VNDK should be deprecated,
and keep it overridable with command for now.

Bug: 301346137
Test: Checked if aosp_cf_x86_64_phone-trunk_staging is VNDK deprecated
Change-Id: Ib9bb48fbfb14d1ab87f939439da4f23e364d1173
diff --git a/core/config.mk b/core/config.mk
index c747fd5..9b66e55 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -813,7 +813,11 @@
 requirements :=
 
 # Set default value of KEEP_VNDK.
-KEEP_VNDK ?= true
+ifeq ($(RELEASE_DEPRECATE_VNDK),true)
+  KEEP_VNDK ?= false
+else
+  KEEP_VNDK ?= true
+endif
 
 # BOARD_PROPERTY_OVERRIDES_SPLIT_ENABLED can be true only if early-mount of
 # partitions is supported. But the early-mount must be supported for full