test: Add missing test case for SegmentIterator
test: Add missing test case for SegmentIterator

Based on discussion of PR #3419

Change-Id: I02bfc615a169b54b94cdc624ace77d9ffefd624e

tvoli/shaka-player,tvoli/shaka-player,shaka-project/shaka-player,tvoli/shaka-player,tvoli/shaka-player,shaka-project/shaka-player,shaka-project/shaka-player,shaka-project/shaka-player