Add versions property to libc_hwasan stubs

bp2build will generate the stub targets only if versions is not empty.

Test: b query //bionic/libc:* | grep libc_hwasan_stub_libs-current

Change-Id: Iac905497ae4955a44b7b29e2d29a2c702c86da8e
diff --git a/libc/Android.bp b/libc/Android.bp
index f5f5f7c..ec9ca0c 100644
--- a/libc/Android.bp
+++ b/libc/Android.bp
@@ -1863,6 +1863,7 @@
     // symlink logic in soong.
     stubs: {
         symbol_file: "libc.map.txt",
+        versions: ["current"],
     },
     native_bridge_supported: false,
     // It is never correct to depend on this directly. This is only