Merge changes I86da8ca8,Ibb58fae9,I9c6a9fa3,I4d1ab599,I818c0f4a, ...

* changes:
  Change libbt-platform-protos dependency
  Update the readme to use build.py and explain Rust
  Add build.py to simplify building locally
  Build support for Rust via Cargo
  Add option to build libbluetooth as staticlib
  Prevent building some codecs when not supported
  Build support and abstractions for Linux build
  Add source_root parameter to bluetooth_packetgen
  Fix bison 3.7 incompatability
  Host tools support