Make syn available to product and vendor am: 4b98a0b558 am: a29266e70b am: 4b3069129f

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/syn/+/2476463

Change-Id: I915db50e3d043c70456209f63a0d7c47fd624378
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
diff --git a/Android.bp b/Android.bp
index 99f27b9..cee562d 100644
--- a/Android.bp
+++ b/Android.bp
@@ -64,8 +64,6 @@
         "libunicode_ident",
     ],
     compile_multilib: "first",
-    apex_available: [
-        "//apex_available:platform",
-        "//apex_available:anyapex",
-    ],
+    product_available: true,
+    vendor_available: true,
 }