[Code Health] Removed expired Drive histograms code

Removed related code for
Drive.TotalFileCountInBatchUpload
Drive.TotalFileSizeInBatchUpload
that expired as of M75. There are already no entries in histograms.xml

Bug: 1384822
Change-Id: Id07c0a2e0becf613147fb79536b9155718bf6c7a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4414589


Reviewed-by: Austin Sullivan <asully@chromium.org>
Commit-Queue: Sergii Bykov <sbykov@google.com>
Cr-Commit-Position: refs/heads/main@{#1128846}