Make unicode-segmentation available to product and vendor am: 312cd17603 am: 3c5f4ce0a5 am: eb9e371b88

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/unicode-segmentation/+/2475806

Change-Id: I9a0f730d78631bc1e328cdf15bca0fffd3d9b1fc
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>