Remove deprecated ExpectationToString in SequenceChecker
Remove deprecated ExpectationToString in SequenceChecker

Bug: webrtc:12419
Change-Id: I501b96865f69f15e49a813c5dcd6ccf44d67c2e7
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/205621
Commit-Queue: Artem Titov <1e27363ccc366a7ff0fdde48204d68d5ebfeccc5@webrtc.org>
Reviewed-by: Mirko Bonadei <d2c43c210eae6feef04f53bae50885e8152edcca@webrtc.org>
Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#33157}

TimothyGu/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,TimothyGu/libilbc