Make open_dice usable in system/authgraph/tests.

Test: compile with this change
Change-Id: Ieeb69e211fc4587dfe67503fdc874a224ac27a6b
diff --git a/libs/dice/open_dice/Android.bp b/libs/dice/open_dice/Android.bp
index 646080d..3fae8a5 100644
--- a/libs/dice/open_dice/Android.bp
+++ b/libs/dice/open_dice/Android.bp
@@ -27,6 +27,7 @@
     ],
     visibility: [
         "//packages/modules/Virtualization:__subpackages__",
+        "//system/authgraph/tests:__subpackages__",
     ],
 }
 
@@ -54,6 +55,7 @@
     ],
     visibility: [
         "//packages/modules/Virtualization:__subpackages__",
+        "//system/authgraph/tests:__subpackages__",
     ],
     apex_available: [
         "//apex_available:platform",