Consolidate ascii spinner stop in devtools activation

[jmagman]

status.stop() in catch was throwing because the timer was already stopped and nulled out. Consolidate the status stop calls into one finally block.

Introduced in #73366
Fixes #75677

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[jonahwilliams]

We really need to make the BufferLogger spinners hit this same assert

[jonahwilliams]

LGTM

The devtools launcher is somewhat standalone, could we write a test with this using a fake logger?

[jmagman]

We really need to make the BufferLogger spinners hit this same assert

That's a good idea.

The devtools launcher is somewhat standalone, could we write a test with this using a fake logger?

There are already tests that exercise the exception case

flutter/packages/flutter_tools/test/general.shard/devtools_launcher_test.dart

Line 206 in f2bb39d

testWithoutContext('DevtoolsLauncher prints error if exception is thrown during activate', () async {

The status.stop() in the catch throws the The method 'cancel' was called on null seen in the crashes.

flutter/packages/flutter_tools/lib/src/devtools_launcher.dart

Lines 155 to 168 in 021311e

	if (_devToolsActivateProcess.exitCode != 0) {
	status.cancel();
	_logger.printError('Error running `pub global activate '
	'devtools`:\n${_devToolsActivateProcess.stderr}');
	return false;
	}
	status.stop();
	_persistentToolState.lastDevToolsActivationTime = DateTime.now();
	return true;
	} on Exception catch (e, _) {
	status.stop();
	_logger.printError('Error running `pub global activate devtools`: $e');
	return false;
	}

So the original exception caught could be:

1. pub global activate succeeds, status.stop() is called, then _persistentToolState.lastDevToolsActivationTime = DateTime.now() throws? I don't see how though, the persisting config seems fine.
   

   flutter/packages/flutter_tools/lib/src/persistent_tool_state.dart

   Lines 148 to 150 in 73506f3

   	set lastDevToolsActivationTime(DateTime time) =>
   	_config.setValue(_kLastDevToolsActivationTimeKey, time.toString());
   	}

2.pub global activate fails, status.cancel() is called, and _logger.printError('Error running pub global activate devtools:\n${_devToolsActivateProcess.stderr}') throws. I don't see how that could be either.

Let me think about how to test this by simulating either one or two.