Generate rules.mk for bit_field crate am: 86f432e8d8 am: 5ddf493d4f

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/bit_field/+/3018284

Change-Id: I8e5a054fbf70ff8c3a7c167925ac43e52313cef3
Signed-off-by: Automerger Merge Worker <[email protected]>