Add comment for the use __uploads attribute on request class for Blobstore API helper.
Add comment for the use __uploads attribute on request class for Blobstore API helper.

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extra : rebase_source : 55b24129e3c50866d410bde7b2b93cc768fff316

SRabbelier/Melange,SRabbelier/Melange,SRabbelier/Melange,SRabbelier/Melange,SRabbelier/Melange,SRabbelier/Melange,SRabbelier/Melange,SRabbelier/Melange,SRabbelier/Melange