Use module name hash instead of the plaintext

* In order to reduce the length of the module names generated through
gn2bp (b/376452102), we're going to use the hash of the module name for
rust modules only, this means that a rust module name will change from

lib{crate_name}_{module_name} -> lib{crate_name}_{first 16 char of hash}

`lib{crate_name}` is a requirement enforced on us by Soong.

Bug: 376452102
Change-Id: Ie1cfa9f36ed954c31e4393238e72d753cd90b883
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5979748
Commit-Queue: Mohannad Farrag <aymanm@google.com>
Auto-Submit: Mohannad Farrag <aymanm@google.com>
Reviewed-by: Stefano Duo <stefanoduo@google.com>
Cr-Commit-Position: refs/heads/main@{#1378387}