Ramp up ampdoc-fie experiment to 10% (5% exp, 5% control) in prod. (ampproject#29663)

Author: lannka

build-system/global-configs/prod-config.json

@@ -12,6 +12,7 @@
   "amp-action-macro": 1,
   "amp-ad-ff-adx-ady": 0.01,
   "amp-auto-ads-adsense-holdout": 0.1,
+  "ampdoc-fie": 0.1,
   "amp-mega-menu": 1,
   "amp-nested-menu": 1,
   "amp-playbuzz": 1,