Fix message descriptions to indicate screenreader use

The wording on the message descriptions was incorrect,
suggesting the text is "readable" when it should have
indicated that the text will be read by a screenreader.

Change-Id: Ide5ae94e938d1690f4adec639484815aaeeddf5e
Reviewed-on: https://chromium-review.googlesource.com/1124800
Commit-Queue: Orin Jaworski <[email protected]>
Reviewed-by: Mark Pearson <[email protected]>
Cr-Commit-Position: refs/heads/master@{#572401}
1 file changed