Dev/jebransyed/android register

[jebrans]

Summary

Enable the mobile-2 Android sample to register itself with TypeAgent as
a client-hosted androidDevice agent using registerClientAgent.

The app supplies an inline schema for alarm and timer actions, receives
typed executeAction callbacks over the existing WebSocket connection,
dispatches them through Android intents, and returns success or failure
results to TypeAgent.

The existing takeAction handlers remain available for compatibility
with the static androidMobile agent.

Example

Before

The Android app depended on the server-side androidMobile agent and
received fire-and-forget client actions:

TypeAgent androidMobile agent -> takeAction("set-timer", ...) -> Android intent

The app could not register its own schema or report the device operation
result to TypeAgent.

After

The Android app registers its own schema and action implementation:

Android app -> registerClientAgent("androidDevice", inlineSchema) -> executeAction(setTimer) -> Android intent -> ActionResult

A deterministic action can be tested with:

@action --parameters {"originalRequest":"timer","durationInSeconds":30} androidDevice setTimer

Timer request sent for 30 seconds