floss: Add support for running cargo-bloat

In order to track how binary space is being used, add support for
calling cargo bloat via build.py. See
https://crates.io/crates/cargo-bloat for more informatio about the crate
which needs to be installed on the host in order to run.

Bug: 356808668
Test: mmm packages/modules/Bluetooth
Change-Id: I637e7e3f48b38ad9982a43ecbe56e51afcf5431b