Open visibility of diced_open_dice to secretkeeper

secretkeeper_client library builds ExplicitAndOwnedDiceArtifacts on the
top of OwnedDiceArtifacts. Other methods to retrieve keys from
DiceArtifacts will also be useful.

Bug: 298217847
Test: Builds
Change-Id: I54da7c3130d96ae70eb59591b89d4cdfc10b111f
diff --git a/libs/dice/open_dice/Android.bp b/libs/dice/open_dice/Android.bp
index 2d0f52c..ea94ebf 100644
--- a/libs/dice/open_dice/Android.bp
+++ b/libs/dice/open_dice/Android.bp
@@ -57,6 +57,7 @@
     visibility: [
         "//packages/modules/Virtualization:__subpackages__",
         "//system/authgraph/tests:__subpackages__",
+        "//system/secretkeeper/client:__subpackages__",
     ],
     apex_available: [
         "//apex_available:platform",