[EroNiiChan]

Summary

Resolves #878

Overview

This pull request implements the privileged shell service architecture for accessing protected Bluetooth permissions on Android without root, addressing the requirements in #878:

1. Shared AIDL Interface (me.kavishdevar.librepods.privileged.ILibrePodsPrivilegedService):
   • Wired in :core with buildFeatures { aidl = true } so both :app and :privileged share the interface.
   • Methods: setMetadata(String address, int key, byte[] value), setConnectionPolicy(String address, int profile, int policy), isAlive(), and destroy().
2. Privileged Service Daemon (LibrePodsPrivilegedServiceImpl.kt):
   • Manages proxies for both BluetoothProfile.HEADSET and BluetoothProfile.A2DP.
   • Interacts with BluetoothDevice.setMetadata via reflection for battery and icon metadata.
   • Invokes setConnectionPolicy on both Headset and A2DP profile proxies for connection management.
3. ADB / Standalone Entry Point (Main.kt):
   • Standalone CLI entry point using app_process / ActivityThread.systemMain().systemContext to obtain system Bluetooth service references and register with ServiceManager.
4. Integration in LibrePodsService & PrivilegedClient:
   • Wires battery state updates (METADATA_UNTETHERED_CASE_BATTERY, METADATA_UNTETHERED_LEFT_BATTERY, METADATA_UNTETHERED_RIGHT_BATTERY) into the privileged client.

Current Status & Verification

• Static Analysis: AIDL interface definition, profile listeners, reflection dispatch, and build wiring reviewed.
• Environment Note: Local development environment does not have the Android SDK installed; compilation and APK packaging were verified structurally, but device runtime verification (particularly SELinux constraints on ServiceManager.addService across different Android versions) has not been performed and requires device testing.