[vs] Extract writable partition initialization into a new library

So that we can reuse this function across various virtualization
services.

Bug: 272226230
Test: atest virtualizationmanager_device_test
Change-Id: I54c142ce8a4163835b312ba70424b63ffc056ae8
diff --git a/libs/vsutil/src/lib.rs b/libs/vsutil/src/lib.rs
new file mode 100644
index 0000000..cac888a
--- /dev/null
+++ b/libs/vsutil/src/lib.rs
@@ -0,0 +1,22 @@
+// Copyright 2023, The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! This library provides utility functions used by both various
+//! Virtualization services.
+
+mod file;
+mod partition;
+
+pub use file::clone_file;
+pub use partition::init_writable_partition;