ticket:10045: Fix number of significant digits with 0.

git-svn-id: http://source.icu-project.org/repos/icu/icu/trunk/source@33487 251d0590-4201-4cf1-90de-194747b24ca1
ticket:10045: Change UNICODE_STRING_SIMPLE to a UnicodeString constructor in an attempt to fix broken builds.

git-svn-id: http://source.icu-project.org/repos/icu/icu/trunk/source@33489 251d0590-4201-4cf1-90de-194747b24ca1