Internal issue: b/218923102

The following call https://github.com/flutter/engine/blob/12609b45685bd988b296595be2bd3ebacb80ba9c/shell/platform/android/external_view_embedder/external_view_embedder.cc#L271-L273 expects to run on the platform thread, but it might be blocked during application startup.

Culprit: flutter/engine#31122