Temporarily disable swcodec in mixed bulid

When aconfig (rust_binary) becomes a transitive dependency of swcodec, mixed build swcodec breaks because the cargo_build_script rust rule declares a directory which is not handled by mixed build yet. See b/307389608 for more context.

A follow-up CL will fix the issue and allow enabling swcodec in mixed build again.

Bug: 307389608
Test: Presubmit
Change-Id: I7ba7b5cd06b231f4867870fe8d0bd53299528fe3