Merge the uptream pull/682 to prepare for Android extra data package

This patch adds 'usePoolBundle' to the build tool. When building
android_small/icudatl_extra.dat, 'userPoolBundle' has to be
set to false.

See https://unicode-org.atlassian.net/browse/ICU-20660 and
https://github.com/unicode-org/icu/pull/682 for details.

Bug: chromium:969181
Change-Id: Ie721d63eaa8426f952d2809c7189574b8f737c1d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/deps/icu/+/1753028
Reviewed-by: Jungshik Shin <jshin@chromium.org>
5 files changed