idsig: Migrate from ring to the openssl crate

Bug: 232676161
Test: atest libidsig.test
Change-Id: Icdda672a802e24f13ca071312d40bc1b44665155
diff --git a/libs/idsig/Android.bp b/libs/idsig/Android.bp
index 3f70a64..2e9c663 100644
--- a/libs/idsig/Android.bp
+++ b/libs/idsig/Android.bp
@@ -11,8 +11,8 @@
     rustlibs: [
         "libanyhow",
         "libbyteorder",
-        "libring",
         "libnum_traits",
+        "libopenssl",
     ],
     proc_macros: ["libnum_derive"],
 }