Make memchr available to product and vendor am: ae75378e8c am: ea6ce3a6c0 am: fe4070a3c5 am: cb0f07e213

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/memchr/+/2475775

Change-Id: I2ac71e93d20f7f79c944b840c3fc6d99c76e6f88
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>