[dice] Move open-dice Rust wrapper libraries to virt

Since these wrapper libraries are only used in virt projects.

The tests are added to busytown config at cl/573729094.

Test: atest MicrodroidHostTests
Change-Id: I2479086c5ee5f1c7ce8884d32cf18f6f4cf07172
diff --git a/libs/dice/OWNERS b/libs/dice/OWNERS
new file mode 100644
index 0000000..fbc501d
--- /dev/null
+++ b/libs/dice/OWNERS
@@ -0,0 +1 @@
+ascull@google.com