Removed close guards for Element and Type objects

Bug: 28053769

These objects are tiny and unlikely to cause memory issues.

In addition, llvm-rs-cc auto-generated code contains such objects, which are
not visibible to developers and impossible to manually destroy, leaving
distracting warnings in Strict Mode.

Test: RsTest with StrictMode on and CTS tests

Change-Id: Iec68cca4f1259124b9f503a230c1a28b97ede1f3