Use Android-specific icudata file

Android build needs to use a separate icu data file. When
icu_use_data_file_flag is on, it has to copy android/icudtl.dat.

The Chrome-side of change is https://codereview.chromium.org/156333002/

BUG=72633
TEST=When rolled in in DEPS, Linux/Mac/Windows builds go as before (i.e. have third_party/icu/source/data/in/icudtl.dat copied to the top build directory).
R=andrewhayden@chromium.org, mark@chromium.org

Review URL: https://codereview.chromium.org/149953006

git-svn-id: https://src.chromium.org/chrome/trunk/deps/third_party/icu46@249466 4ff67af0-8c30-449e-8e8b-ad334ec8d88c