Autoroller: Add --ignore-unclean-workdir flag
Autoroller: Add --ignore-unclean-workdir flag

Add a flag that makes the script more useful for local development, when
you normally develop on a local branch.

BUG=webrtc:5006
NOTRY=True

Review-Url: https://codereview.webrtc.org/2566223007
Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#15602}

ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,TimothyGu/libilbc