[omnibox] 2nd attempt to reland https://crrev.com/c/4209512:

"update on device provider to support tail model (Part#2/2)"

We are trying to guard all occurrences of model executor and related
code using build flag "BUILD_WITH_TFLITE_LIB".

Patchset:
PS#2: https://crrev.com/c/4214438
PS#3: Add fix to https://crrev.com/c/4214438, and turn off build flag BUILD_WITH_TFLITE_LIB; try job looks okay.
PS#4: Add fix.

Bug: 1372112
Change-Id: I31be62bdefe86cfe5c42fb514b298022e7d74f49
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4220351
Reviewed-by: Sophie Chang <sophiechang@chromium.org>
Commit-Queue: C Ch <cch@chromium.org>
Reviewed-by: Orin Jaworski <orinj@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1101107}