`Linux linux_fuchsia_tests` flakey with `embedder_tests.cm`

This flake has happened 9/50 of the last runs.

## examples
- https://ci.chromium.org/ui/p/flutter/builders/prod/Linux%20Production%20Engine%20Drone/1554208/overview
- https://ci.chromium.org/ui/p/flutter/builders/prod/Linux%20Production%20Engine%20Drone/1553836/overview
- https://ci.chromium.org/ui/p/flutter/builders/prod/Linux%20linux_fuchsia_tests/9395/overview

## log
```
[ RUN ] EmbedderTest.CanGetVulkanEmbedderContext
[stderr - main]
embedder.cc (2041): 'FlutterEngineInitialize' returned 'kInvalidArguments'. The assets path in the Flutter project arguments was missing.
embedder.cc (3030): 'FlutterEngineSendPlatformMessage' returned 'kInvalidArguments'. Message size was non-zero but the message data was nullptr.
embedder.cc (2500): 'FlutterEngineRunInitialized' returned 'kInvalidArguments'. Engine handle was invalid.
embedder.cc (2500): 'FlutterEngineRunInitialized' returned 'kInvalidArguments'. Engine handle was invalid.
embedder.cc (2709): 'FlutterEngineSendWindowMetricsEvent' returned 'kInvalidArguments'. Viewport metrics were invalid.
embedder.cc (2603): 'FlutterEngineRemoveView' returned 'kInvalidArguments'. Remove view info was invalid. The implicit view cannot be removed.
embedder.cc (3426): 'FlutterEngineUpdateLocales' returned 'kInvalidArguments'. Language code is required but not present in FlutterLocale.
embedder.cc (2500): 'FlutterEngineRunInitialized' returned 'kInvalidArguments'. Engine handle was invalid.
embedder.cc (2700): 'FlutterEngineSendWindowMetricsEvent' returned 'kInvalidArguments'. Device pixel ratio was invalid. It must be greater than zero.
embedder.cc (2700): 'FlutterEngineSendWindowMetricsEvent' returned 'kInvalidArguments'. Physical view insets are invalid. They must be non-negative.
embedder.cc (2700): 'FlutterEngineSendWindowMetricsEvent' returned 'kInvalidArguments'. Physical view insets are invalid. They cannot be greater than physical height or width.
embedder.cc (2700): 'FlutterEngineSendWindowMetricsEvent' returned 'kInvalidArguments'. Window metrics are invalid. Width and height must be within the specified constraints.
embedder.cc (2700): 'FlutterEngineSendWindowMetricsEvent' returned 'kInvalidArguments'. Window metrics are invalid. Width and height must be within the specified constraints.
embedder.cc (2700): 'FlutterEngineSendWindowMetricsEvent' returned 'kInvalidArguments'. Window metrics are invalid. Width and height must be within the specified constraints.
[FAILED] main

Failed tests: main
0 out of 1 tests passed...
fuchsia-pkg://fuchsia.com/embedder_tests#meta/embedder_tests.cm completed with result: FAILED
Tests failed.
```