Changes to make this work:

- Had to change the use of an UBool constant `FALSE` to 0 because
  the file referring to it does not include the respective header.

- Had to change the license checker to ignore files in the directory
  icu/source/samples.  There were random changes to the licensing
  headers which tripped up license checks.  And since we don't include
  samples in the binaries we build, the most efficient way to fix it is
  to exclude sample code from license checks.

Issue: https://github.com/flutter/flutter/issues/70370

This removes the Window class, now that the framework no longer uses it.

* remove the extra values which was overshadowing the test result

* increase difference. canvaskit gives different results

* increase difference more. firefox gave 1.7 diff. add comments

Limit heap growth to half of totalMem by default, with the option to set it higher or lower in the AndroidManifest

This reverts commit d37b8621, relanding #22267, now that flutter/flutter#70252 has landed to prevent the problems it had the first time.

Here is the original PR description:

For some reason (probably a bad merge on my part), the return values for locale and locales are not the same on web as they are on other platforms for the PlatformDispatcher and SingletonFlutterWindow classes. The web versions are non-nullable and the others are nullable.

This converts them to be the same (non-nullable) values

Instead of synchronousResizing flag which in some cases seems to be set too early, synchronous resizing is postponed until framework produces a frame so ResizeSynchronizer knows for sure that the engine is up and running.

FontLanguageListCache.cpp uses the ICU constant FALSE of type UBool, but
does not #include <umachine.h> where it is defined.

This makes the code brittle with respect to header file reorganization,
and I found this while trying to roll ICU version 68.1 to Flutter
engine.

For https://github.com/flutter/flutter/issues/70349

* Revert "Remove GetExternalViewEmbedder from surface (#22272)"

This reverts commit 5419f70f.

* Revert "Rasterizer is initialized with an external view embedder (#22405)"

This reverts commit f95df42e.

This reverts commit dc886418.