Revert "Adding gclient_gn_args_file to WebRTC DEPS."
Revert "Adding gclient_gn_args_file to WebRTC DEPS."

This reverts commit f0e88d4601a7cdbb97359dae18bb1f01ee18e99f.

Reason for revert: This should not be needed after:
https://chromium-review.googlesource.com/1028571

Original change's description:
> Adding gclient_gn_args_file to WebRTC DEPS.
>
> In order to unblock the Chromium Roll into WebRTC this CL tells gclient
> to generate build/config/gclient_args.gni with the value of
> checkout_android.
>
> Bug: None
> Change-Id: Iaca047ab5886545d0c9f3228099d8e8a914842e4
> Reviewed-on: https://webrtc-review.googlesource.com/72040
> Reviewed-by: Oleh Prypin <5baa3e04f9bd6ba7a2a4b56625a3c84f19237cdb@webrtc.org>
> Commit-Queue: Mirko Bonadei <d2c43c210eae6feef04f53bae50885e8152edcca@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#22996}

No-Try: True
Bug: chromium:836344
Change-Id: Ief0ca65b63e80bcb1d379f667d1e55e7d665d546
Reviewed-on: https://webrtc-review.googlesource.com/72680
Commit-Queue: Oleh Prypin <5baa3e04f9bd6ba7a2a4b56625a3c84f19237cdb@webrtc.org>
Reviewed-by: Oleh Prypin <5baa3e04f9bd6ba7a2a4b56625a3c84f19237cdb@webrtc.org>
Reviewed-by: Mirko Bonadei <d2c43c210eae6feef04f53bae50885e8152edcca@webrtc.org>
Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#23033}
ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,TimothyGu/libilbc