Add vendor visibility and expose root trust anchor json file.

go/p2wu-keystore

Bug: 462505734
Change-Id: Ib23a876c112d154751ff63d4c16e4c756c5ff68c

Android.bp

diff --git a/Android.bp b/Android.bp
index b4669aa..0f86e5b 100644
--- a/Android.bp
+++ b/Android.bp
@@ -29,5 +29,13 @@
     ],
     sdk_version: "36",
     min_sdk_version: "26",
-    visibility: ["//frameworks/base/core/java"],
+    visibility: [
+        "//frameworks/base/core/java",
+        "//vendor:__subpackages__",
+    ],
+}
+
+filegroup {
+    name: "keyattestation_roots",
+    srcs: ["roots.json"],
 }