Mark "u2fDevices" permission stable.

extensions/common/api/_permission_features.json

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This features file defines permissions for extension APIs implemented
 // under src/extensions.
 
 // See extensions/common/features/* to understand this file, in particular
 // feature.h, simple_feature.h, and base_feature_provider.h.
 
@@ skipping 105 matching lines @@
       "channel": "stable",
       "extension_types": ["extension"],
       "whitelist": [
         "496B6890097EB6E19809ADEADD095A8721FBB2E0",  // FIDO U2F APIs
         "E24F1786D842E91E74C27929B0B3715A4689A473"   // CryptoToken
       ]
     }
   ],
   "u2fDevices": [
     {
-      "channel": "dev",
+      "channel": "stable",
       "extension_types": ["extension", "platform_app"],
       "whitelist": [
         "496B6890097EB6E19809ADEADD095A8721FBB2E0",  // FIDO U2F APIs
         "E24F1786D842E91E74C27929B0B3715A4689A473",  // CryptoToken
         "6F9E349A0561C78A0D3F41496FE521C5151C7F71",  // Security Key
         "C06709A259378015404ED20F75C7D08547E0F10B"   // Security Key (dev)
       ]
     }
   ],
   "power": {
@@ skipping 141 matching lines @@
       // addressed. Tracked in crbug/285151.
       "channel": "stable",
       "extension_types": ["extension"],
       "location": "component",
       "whitelist": [
         "D519188F86D9ACCEE0412007B227D9936EB9676B"  // GAIA Component Extension
       ]
     }
   ]
 }