Windows framework_tests_libraries_leak_tracking is 3.85% flaky

[fluttergithubbot]

The post-submit test builder Windows framework_tests_libraries_leak_tracking had a flaky ratio 3.85% for the past (up to) 100 commits, which is above our 2.00% threshold.

One recent flaky example for a same commit: https://ci.chromium.org/ui/p/flutter/builders/prod/Windows%20framework_tests_libraries_leak_tracking/81 Commit: https://github.com/flutter/flutter/commit/4de32b870212f33610be0ec122001d695f373a77

Flaky builds: https://ci.chromium.org/ui/p/flutter/builders/prod/Windows%20framework_tests_libraries_leak_tracking/81 https://ci.chromium.org/ui/p/flutter/builders/prod/Windows%20framework_tests_libraries_leak_tracking/71 https://ci.chromium.org/ui/p/flutter/builders/prod/Windows%20framework_tests_libraries_leak_tracking/48

Recent test runs: https://flutter-dashboard.appspot.com/#/build?taskFilter=Windows%20framework_tests_libraries_leak_tracking

Please follow https://github.com/flutter/flutter/blob/master/docs/infra/Reducing-Test-Flakiness.md#fixing-flaky-tests to fix the flakiness and enable the test back after validating the fix (internal dashboard to validate: go/flutter_test_flakiness).

[Piinks]

cc @polina-c

[Piinks]

This test shard was just recently made blocking.