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