Add E2E tests for aidlcli against Android emulator

Tests exercise aidlcli commands via adb shell on a real (or emulated)
Android device. TestMain manages the emulator lifecycle: starts it
headlessly if no device is connected, builds and pushes the aidlcli
binary, then tears down on exit. Each test invokes a specific aidlcli
subcommand with --format json and validates the JSON output structure.

Covered services: ServiceManager (list/inspect), LocationManager,
ActivityManager, PackageManager, PowerManager, ThermalService,
DisplayManager, Clipboard, Telephony, and several HAL services
(WiFi supplicant, Camera, Bluetooth) that skip gracefully when
unavailable on the emulator.

Author: xaionaro@dx.center