message: fix(manifest): fix browser global conflict
diff: "content_scripts": [
  {
  - "js": [
  - "static/browser-polyfill.min.js",
  - "content.js"
  - ],
  + "js": ["static/browser-polyfill.min.js"],
  + "matches": ["<all_urls>"],
  + "run_at": "document_start",
  + "match_about_blank": true,
  + "all_frames": true
  + },
  + {
  + "js": ["content.js"],
  "css": ["content.css"],
  "matches": ["<all_urls>"]
  },
  {
  - "js": [
  - "static/browser-polyfill.min.js",
  - "selection.js"
  - ],
  + "js": ["selection.js"],
  "matches": ["<all_urls>"],
  "match_about_blank": true,
  "all_frames": true
  