//! Android driver: adb client, agent deploy, agent session and emulator gRPC.
//!
//! - [`adb`] speaks the adb server's smart-socket protocol with the driver's
//! own client (design D3).
//! - [`agent`] deploys the resident agent, reuses or replaces a running one
//! and connects to it (design D2 and D3).
//! - [`emulator`] drives the emulator's gRPC controller, the emulator fast
//! path (design D7).
//! - [`session`] puts an attached agent, and the controller when there is
//! one, behind the mirror's backend traits (design D5 and D7).