Adding a way to disable public_deps presubmit check.
Adding a way to disable public_deps presubmit check.

This is useful when someone is just moving code around or when there is
a good reason to use public_deps.

Example of the error message:
** Presubmit ERRORS **
public_deps is discouraged in WebRTC BUILD.gn files because it doesn't
map well to downstream build systems.
Used in: BUILD.gn (line 31).
If you are not adding this code (e.g. you are just moving existing code)
or you have a good reason, you can add a comment on the line that causes
the problem:

public_deps = [  # no-presubmit-check TODO(webrtc:8603)

Bug: webrtc:8603
Change-Id: If2645b6ba60c7cbf5416450cf6e5a8c08bf4934e
Reviewed-on: https://webrtc-review.googlesource.com/75508
Reviewed-by: Patrik Höglund <b486136ee68458b09c92c86c39f451c87d6ef6a1@webrtc.org>
Commit-Queue: Mirko Bonadei <d2c43c210eae6feef04f53bae50885e8152edcca@webrtc.org>
Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#23186}
ShiftMediaProject/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc