Delete dead code in tensor flow native models


Only Inference() is declared in the header and the rest of these ops aren't used in the current models.

Change-Id: Ib5c5f6e85d5783c2d8e0ca88c1c89cd389e43c21
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6799110
Reviewed-by: Kouhei Ueno <kouhei@chromium.org>
Auto-Submit: Stephen Nusko <nuskos@chromium.org>
Commit-Queue: Stephen Nusko <nuskos@chromium.org>
Reviewed-by: Hidehiko Abe <hidehiko@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1503906}