ticket:9914: Fix DateIntervalFormat so that it will not pad years with 0's

git-svn-id: http://source.icu-project.org/repos/icu/icu/branches/tkeep@33240 251d0590-4201-4cf1-90de-194747b24ca1
ticket:9914: Merge r32219 to r32242 from trunk.

git-svn-id: http://source.icu-project.org/repos/icu/icu/branches/tkeep@33244 251d0590-4201-4cf1-90de-194747b24ca1