BTBrl: Give ChromeVox bluetooth and bluetoothPrivate perms

This change is in preparation for ChromeVox bluetooth braille support.

Bug: 882261,899052
Test: call chrome.bluetooth.startDiscovery(); obtain address to bt braille display; chrome.bluetoothPrivate.connect(); verify ChromeVox displays braille over bt after restarting brltty with -d "bluetooth:<addrr>".
Change-Id: I4df43484de9d4bacd05d72fa6406820ee7c0aa2d
Reviewed-on: https://chromium-review.googlesource.com/c/1299577Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
Reviewed-by: Yuki Awano <yawano@chromium.org>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Commit-Queue: David Tseng <dtseng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#603125}

chrome/browser/resources/chromeos/chromevox/manifest.json.jinja2

@@ -12,9 +12,11 @@
   "background": {
     "page": "cvox2/background/background.html"
   },
+  "bluetooth": {},
   "permissions": [
     "accessibilityPrivate",
     "audio",
+    "bluetoothPrivate",
     "bookmarks",
     "brailleDisplayPrivate",
     "clipboardRead",

extensions/common/api/_manifest_features.json

@@ -83,6 +83,13 @@
       "81986D4F846CEDDDB962643FA501D1780DD441BB",  // http://crbug.com/407693
       "A9A9FC0228ADF541F0334F22BEFB8F9C245B21D7"   // http://crbug.com/839189
     ]
+  }, {
+    "channel": "stable",
+    "extension_types": ["extension"],
+    "platforms": ["chromeos"],
+    "whitelist": [
+      "75C7F4B720314B6CB1B5817CD86089DB95CD2461"  // http://crbug.com/899052
+    ]
   }],
   "content_capabilities": [{
     "channel": "stable",

extensions/common/api/_permission_features.json

@@ -131,7 +131,8 @@
      ]
     }
   ],
-  "bluetoothPrivate": {
+  "bluetoothPrivate": [
+    {
       "channel": "stable",
       "extension_types": ["platform_app"],
       "platforms": ["chromeos", "win", "mac", "linux"],
@@ -158,6 +159,15 @@
         "A9A9FC0228ADF541F0334F22BEFB8F9C245B21D7"   // http://crbug.com/839189
       ]
     },
+    {
+      "channel": "stable",
+      "extension_types": ["extension"],
+      "platforms": ["chromeos"],
+      "whitelist": [
+        "75C7F4B720314B6CB1B5817CD86089DB95CD2461"  // http://crbug.com/899052
+      ]
+    }
+  ],
   "cast": {
     "channel": "stable",
     "extension_types": ["extension", "legacy_packaged_app", "platform_app"],