Add //tools/netsim:__subpackages__ to extra bp file.

This was added to Android.bp in https://r.android.com/2820189 without
adding it here, so it would be removed by re-running cargo2andriod.py.

Bug: 305723170
Test: Ran cargo2android.py
Change-Id: I5e368d4cd7720ea538ba9b5a8cafb72a36d69904
diff --git a/cargo2android_toplevel.bp b/cargo2android_toplevel.bp
index 123dff1..14057e1 100644
--- a/cargo2android_toplevel.bp
+++ b/cargo2android_toplevel.bp
@@ -7,6 +7,7 @@
         "//system/nfc:__subpackages__",
         "//external/uwb/src",
         "//packages/modules/Bluetooth:__subpackages__",
+        "//tools/netsim:__subpackages__",
     ],
 }