Utilize high_priority_deps in autogenerated filesystem modules

The auto generated prebuilt_* module will be listed in
high_priority_deps property of the auto generated filesystem module if
it is listed in the allowlist. The allowlist is empty in aosp, but will
be extended in internal via a soong plugin.

Test: m nothing
Bug: 375053752
Change-Id: Iaa7291bebf8732f47f8da70421a787dfd275b621
diff --git a/fsgen/Android.bp b/fsgen/Android.bp
index 9fa9557..baf9291 100644
--- a/fsgen/Android.bp
+++ b/fsgen/Android.bp
@@ -18,6 +18,7 @@
         "filesystem_creator_test.go",
     ],
     pluginFor: ["soong_build"],
+    visibility: ["//visibility:public"],
 }
 
 soong_filesystem_creator {