New formula: fb-adb

fb-adb is a tool for interacting with Android systems. It does much of what adb does, but with better remote shell support and, hopefully, fewer bugs.

I had submitted a pull request #31555. Because fb-adb didn't have any stable releases, It has been closed.

I had submitted this PR on homebrew-headonly.
https://github.com/Homebrew/homebrew-headonly/pull/58

Now fb-adb has a first tagged version, fb-adb 1.2.0. So I just made another pull request for this version of fb-adb.
https://github.com/facebook/fb-adb/issues/4
Ok. Let's just leave the `update.sh` bit out as I feel a bit uneasy installing something into another package in the test of another.