Restrict visibility to existing user.

We are trying to remove this library, so nobody new should use it.

Test: m rust
Change-Id: Iba886de997ac1875ef65d467cb3f5146609c2a79

Android.bp

diff --git a/Android.bp b/Android.bp
index d52e885..b063d70 100644
--- a/Android.bp
+++ b/Android.bp
@@ -62,4 +62,5 @@
     ],
     product_available: true,
     vendor_available: true,
+    visibility: ["//vendor:__subpackages__"],
 }

cargo_embargo.json

diff --git a/cargo_embargo.json b/cargo_embargo.json
index b5493bc..2826d02 100644
--- a/cargo_embargo.json
+++ b/cargo_embargo.json
@@ -3,6 +3,11 @@
     "//apex_available:platform",
     "com.android.virt"
   ],
+  "module_visibility": {
+    "libx509_parser": [
+      "//vendor:__subpackages__"
+    ]
+  },
   "package": {
     "x509-parser": {
       "dep_blocklist": [