[fuchsia] Add new feature to sandbox policies.

Context: https://fuchsia.googlesource.com/garnet/+/84a4bc12b8613fa2c85c528929a65603fecb3f39
This feature allows us to transition to explicit service sandboxes.

Change-Id: I158a3c454f02f6b72565d04bdc5c41e284bca301
Reviewed-on: https://chromium-review.googlesource.com/1178227
Commit-Queue: P.Y. Laligand <pylaligand@google.com>
Reviewed-by: Sergey Ulanov <sergeyu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#583717}

build/config/fuchsia/sandbox_policy

 {
-  "features": [ "persistent-storage", "root-ssl-certificates", "system-temp" ]
+  "features": [ "persistent-storage", "root-ssl-certificates", "system-temp",
+      "deprecated-all-services" ]
 }
-

build/config/fuchsia/testing_sandbox_policy

 {
-  "features": [ "persistent-storage", "root-ssl-certificates", "system-temp"],
+  "features": [ "persistent-storage", "root-ssl-certificates", "system-temp",
+      "deprecated-all-services" ],
   "dev": ["null", "zero"]
 }
-