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