[Fuchsia] Add "root-ssl-certificates" feature in content_shell.cmx

content_shell runs https stack, so it depends on the root certs.

Bug: 1067477
Change-Id: I84ef67be195870488e886afe2dee9c182bb62e0b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2447038
Auto-Submit: Sergey Ulanov <sergeyu@chromium.org>
Commit-Queue: Wez <wez@chromium.org>
Reviewed-by: Wez <wez@chromium.org>
Cr-Commit-Position: refs/heads/master@{#815718}

content/shell/fuchsia/content_shell.cmx

@@ -4,6 +4,7 @@
       "deprecated-ambient-replace-as-executable",
       "isolated-persistent-storage",
       "isolated-temp",
+      "root-ssl-certificates",
       "vulkan"
     ],
     "services": [