dhcp: disable dnsmasq's DNS function

Disable DNS function within dhcp container as there's a conflict with
dns-proxy service on new releases of ChromeOS.

BUG=b:409849827
TEST=manual

Change-Id: I86ad3894bad18c5cc9fe17073416eb604491d516
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/moblab/+/6459628
Reviewed-by: Przemysław Filipek <[email protected]>
Commit-Queue: Tomasz Jakubowski <[email protected]>
Reviewed-by: Rafał Gaweł <[email protected]>
Tested-by: Tomasz Jakubowski <[email protected]>
2 files changed