aw: Set enable/disable feature once

Previous implementation appended a new --enable-feature or
--disable-feature switch for every hard coded feature. Command line argv
turned out to be append only, even though there is a remove switch

Change to a scoped class and append each at most only one.

Change-Id: Ic0243d69bf23038c17a31a76f32ff2a88505028c
Commit-Queue: Bo <>
Reviewed-by: Nate Fischer <>
Cr-Commit-Position: refs/heads/master@{#641830}
8 files changed