Add cc static library for fsverity digests

Bug: 203483081
Test: build
Change-Id: I68722ff6942d98ea8a980ff217f59edacb3117f4
diff --git a/fsverity/Android.bp b/fsverity/Android.bp
index 5c3d6a0..2fc3c01 100644
--- a/fsverity/Android.bp
+++ b/fsverity/Android.bp
@@ -53,3 +53,14 @@
         "com.android.compos",
     ],
 }
+
+cc_library_static {
+    name: "libfsverity_digests_proto_cc",
+    proto: {
+        type: "lite",
+        static: true,
+        canonical_path_from_root: false,
+        export_proto_headers: true,
+    },
+    srcs: ["fsverity_digests.proto"],
+}