Make num_cpus available to product and vendor

Bug: 270690570

Test: mma in external/rust/crates
Change-Id: I2eff2db44b6d1874d0666165ada3bfdf08c21932
diff --git a/Android.bp b/Android.bp
index 83e601a..422335c 100644
--- a/Android.bp
+++ b/Android.bp
@@ -56,6 +56,7 @@
         "com.android.uwb",
         "com.android.virt",
     ],
+    product_available: true,
     vendor_available: true,
     min_sdk_version: "29",
 }