Update trim_data to deal with locale fallback failure for units

Delete empty units,units{Narrow,Short} blocks after trimming units data.
Empty units* blocks in en_GB and a few other locales after trimming
causes ICU to fail to fall back to get the duration data for those
locales.

In addition, fix source/data/translit/root_subset.txt. Rule*Ids block has
to be present even though it's empty. When dropping Hans-Hant transform
rules, root_subset.txt was changed to be completely empty, which broke
"components_unittests --g_test_filter=AutofillProfileComparato*" .

With these changes, regenerate ICU data files. The size is slightly smaller.

android/icudtl.dat  6573872 => 6573792
common/icudt*dat    10130560 => 10130480

BUG=707515,677043,684609
TEST=components_unittests --gtest_filter=AutofillProfileComparato*
TEST=ui_base_unittests --gtest_filter=L10nUtilTest.TimeDurationForm*
R=derat@chromium.org

Review-Url: https://codereview.chromium.org/2812943003 .