Fix annoying (but non-fatal) java doc error.

IcuIteratorWrapper.java references com.ibm.icu.text.BreakIterator,
which is renamed by our jarjar rule, and so unrecognizable by javadoc,
with annoying error: error: package com.ibm.icu.text does not exist.
We don't want to generate doc for this file anyway.

Change-Id: I815eff9d174561be9a380dd7374800cf25d6ca7a