Remove const qualifier from generateConfigs Requested in https://chromium-review.googlesource.com/349353 BUG=angleproject:1362 Change-Id: I989757c2fb8f65d5afcfb177b7f8da1414871e6f Reviewed-on: https://chromium-review.googlesource.com/349694 Reviewed-by: Corentin Wallez <cwallez@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Yuly Novikov <ynovikov@chromium.org>