DartIsolateTest.PlatformIsolateSendAndReceive is flaky #156251
Description
Example flake:
[23/80] DartIsolateTest.PlatformIsolateSendAndReceive (144 ms)
[INFO:flutter/testing/test_timeout_listener.cc(76)] Test timeout of 300 seconds per test case will be enforced.
�[0;33mNote: Google Test filter = DartIsolateTest.PlatformIsolateSendAndReceive
�[m�[0;32m[==========] �[mRunning 1 test from 1 test suite.
�[0;32m[----------] �[mGlobal test environment set-up.
�[0;32m[----------] �[m1 test from DartIsolateTest
�[0;32m[ RUN ] �[mDartIsolateTest.PlatformIsolateSendAndReceive
[23/80] DartIsolateTest.PlatformIsolateSendAndReceive returned/aborted with exit code -11 (144 ms)
[24/80] DartIsolateTest.PlatformIsolateSendAndReceive (146 ms)I have seen this occur enough times (it's blocked pre-submit on PRs more than 3x this week for me alone).