Remove unneccessary flag.

This is now the default.

Test: Ran cargo2android.py, no difference in Android.bp.
Change-Id: I6b6281ea6e82e0ee071bdbc1218087962ae77832
diff --git a/cargo2android.json b/cargo2android.json
index ed3dae4..4f669f8 100644
--- a/cargo2android.json
+++ b/cargo2android.json
@@ -6,7 +6,6 @@
   "device": true,
   "min_sdk_version": "29",
   "run": true,
-  "vendor-available": true,
   "variants": [
     {
       "features": "default,derive,rc",