The UsbDebuggingManager listens to adbd requests and displays a dialog
when the public key authentification fails, for the user to confirm if it
wants to allow USB debugging from the attached host. If the user chooses
to always allow USB debugging, the UsbDebuggingManager writes the public
key to adbd's config file so that the public key authenfication succeeds
next time.
Change-Id: I115c828331d8e326c380844ee33915d5dff22260
4e68bd420b