docs: Fixing typo in class summary

The commontypos linter complained about the "the the" typo.
No change to source code.

Per go/fix-refdocs, master is now the preferred branch for doc fixes until the U dev branch is open. Since this CL hasn't been reviewed yet, I'm CPing it over here and abandoning the original CL.

Bug: 263824202
Change-Id: If03bfc1f3e1a42b26019c039595c7bf8c0010ad4
Test: [go/abtd docs build]