[fuchsia] Make `pm serve` run silently.

"pm serve" runs reliably and no longer needs to run verbosely.
The remaining issues with amber-based deployments tend to be on the
device, not on the HTTP server.

This change prevents a lot of httpd log spam from being sent to the
console.

Bug: 895627
Change-Id: If5e63785c8d70568bd4b1b99a18f4c59acc2a48e
Reviewed-on: https://chromium-review.googlesource.com/c/1407255
Commit-Queue: Kevin Marshall <kmarshall@chromium.org>
Commit-Queue: Wez <wez@chromium.org>
Reviewed-by: Wez <wez@chromium.org>
Cr-Commit-Position: refs/heads/master@{#622272}
1 file changed