Autoroller: don't run presubmit hooks
Autoroller: don't run presubmit hooks

The presubmit lint checks require GN but it is not downloaded because runhooks is avoided on the autoroller bot.
The trybots in Gerrit UI should catch the same errors anyway, if they somehow happen.

Also minor cleanup of obsolete flag

No-Try: True
Bug: chromium:836566
Change-Id: I8bf03b8e155343f723c6fdda37210d9161da984c
Reviewed-on: https://webrtc-review.googlesource.com/c/103620
Commit-Queue: Oleh Prypin <5baa3e04f9bd6ba7a2a4b56625a3c84f19237cdb@webrtc.org>
Reviewed-by: Patrik Höglund <b486136ee68458b09c92c86c39f451c87d6ef6a1@webrtc.org>
Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#24967}
TimothyGu/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc