Returns the explain stats in an encoded proto format, as returned from the Firestore backend.
The caller is responsible for unpacking this proto message.
When explain stats were requested with outputFormat = 'text', this returns the explain stats
string verbatim as returned from the Firestore backend.
If explain stats were requested with outputFormat = 'json', this returns the explain stats
as stringified JSON, which was returned from the Firestore backend.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2026-01-23 UTC."],[],[]]
