Add a tool to inject HCI commands into bluedroid.

This tool is very primitive in a number of ways. First, each new
HCI command needs to be carefully crafted. Second, it is entirely
stateless and operates in "fire-and-forget" mode. In other words,
there's no "read-modify-write" capability yet. That being said,
this tool will grow along with the infrastructure in bluedroid.
2 files changed