Revert "Make sure all isolates start during flutter driver tests."

[jonahwilliams]

Reverts #61841

Numerous devicelab tests are broken by this change, specifically new_gallery_ios_transition_perf. It is not clear from the logs what is going wrong

[jonahwilliams]

Landing to fix build

[speaking-in-code]

@jonahwilliams I can take a swing at fixing the devicelab tests. Is there documentation on how to run them?

[acoutts]

Could this be related? I can only run my driver test about 50% of the time. When it fails, the app hangs at the initial splash screen (before dart isolate runs), and the log says this when I run on android:

I/flutter ( 8128): Observatory listening on http://127.0.0.1:33085/6hDv8THcFWg=/
E/FlutterFcmService( 8128): Fatal: failed to find callback
00:00 +0: Bottlepay app SkSL warmup (setUpAll)

VMServiceFlutterDriver: Connecting to Flutter application at http://127.0.0.1:58315/6hDv8THcFWg=/
VMServiceFlutterDriver: Isolate found with number: 1476990802004759
VMServiceFlutterDriver: Isolate is paused at start.
VMServiceFlutterDriver: Attempting to resume isolate
VMServiceFlutterDriver: Connected to Flutter application.
Unexpected <collected> sentinel.

VMServiceFlutterDriver: waitForCondition message is taking a long time to complete...

And it's dead at this point until I uninstall the app and try again.

I am using the "IsolatesWorkaround" and Flutter 1.21.0-1.0.pre:

    // Connect to the Flutter driver before running any tests.
    setUpAll(() async {
      driver = await FlutterDriver.connect();
      workaround = IsolatesWorkaround(driver);
      await workaround.resumeIsolates();
      await driver.waitUntilFirstFrameRasterized();
    });

    // Close the connection to the driver after the tests have completed.
    tearDownAll(() async {
      if (driver != null) {
        await driver.close();
        await workaround.tearDown();
      }
    });

Using print statements I found it's hanging on await driver.waitUntilFirstFrameRasterized();.

Edit
After doing a flutter clean, removing the entire pub_cache directory, uninstalling the app from the device and trying again, I got it to work again.

[guidezpl]

@acoutts Looks like it to me. Follow #24703 for updates