Presigned V4 post policy. Instances of PostPolicyV4 include a URL and a map of fields
that can be specified in an HTML form to submit a POST request to upload an object.
See POST Object for
details of upload by using HTML forms.
See Storage#generateSignedPostPolicyV4(BlobInfo, long, TimeUnit,
PostPolicyV4.PostFieldsV4, PostPolicyV4.PostConditionsV4, Storage.PostPolicyV4Option...) for
example of usage.
[[["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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2026-03-14 UTC."],[],[]]