[mutianf]

Add Cloud Bigtable accelerator daemon lifecycle system tests (test_lifecycle_async.py, test_lifecycle_autogen.py) verifying subprocess/UDS tempdir reaping, zero process/FD/tempdir leaks across repeated lifecycles, crash teardown, and orphan exit on owner SIGKILL.

Part of Stack #18691 (stacked on #18787).

[gemini-code-assist]

Code Review

This pull request introduces system tests for the Bigtable accelerator daemon lifecycle, including both asynchronous (test_lifecycle_async.py) and auto-generated synchronous (test_lifecycle_autogen.py) test suites. The tests verify daemon reaping, resource reclamation after crashes, and leak prevention. Feedback on the changes highlights that the asynchronous test file uses synchronous time.sleep() calls inside async def methods, which blocks the event loop. It is recommended to import asyncio and replace these with non-blocking await asyncio.sleep() calls.

[gemini-code-assist]

Import asyncio to enable non-blocking sleeps in asynchronous test methods.

Suggested change

	import multiprocessing
	import os
	import shutil
	import signal
	import time
	import uuid
	import asyncio
	import multiprocessing
	import os
	import shutil
	import signal
	import time
	import uuid

[gemini-code-assist]

Using synchronous time.sleep() inside an async def test method blocks the entire event loop. Use await asyncio.sleep() instead to keep the event loop responsive.

Suggested change

	time.sleep(0.05)
	await asyncio.sleep(0.05)

[gemini-code-assist]

Using synchronous time.sleep() inside an async def test method blocks the entire event loop. Use await asyncio.sleep() instead to keep the event loop responsive.

Suggested change

	time.sleep(0.1)
	await asyncio.sleep(0.1)