chore(i18n): Translated using Weblate (Japanese)

Currently translated at 99.5% (421 of 423 strings)

Translation: th-ch/youtube-music/i18n
Translate-URL: https://hosted.weblate.org/projects/youtube-music/i18n/ja/

src/i18n/resources/ja.json

@@ -623,6 +623,7 @@
       "name": "通知"
     },
     "performance-improvement": {
+      "description": "実験的スクリプトを有効にすることによってパフォーマンス改善する",
       "name": "パフォーマンス改善 [ベータ]"
     },
     "picture-in-picture": {