Files app/Audio Player: Remove unused permission for mediaPlayerPrivate

Bug: 1162999
Change-Id: If05ffc74b5b7c4977892521a512a6a91d5060f70
Fixed: 1162999
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2620120
Auto-Submit: Luciano Pacheco <lucmult@chromium.org>
Commit-Queue: Josh Simmons <simmonsjosh@google.com>
Reviewed-by: Josh Simmons <simmonsjosh@google.com>
Cr-Commit-Position: refs/heads/master@{#842229}

ui/file_manager/audio_player/manifest.json

@@ -25,7 +25,6 @@
       "fileSystem": ["requestFileSystem", "write"]
     },
     "fullscreen",
-    "mediaPlayerPrivate",
     "power",
     "storage",
     "chrome://resources/",

ui/file_manager/file_manager/manifest.json

@@ -36,7 +36,6 @@
     "https://drive.google.com/",
     "https://www.google-analytics.com/",
     "launcherSearchProvider",
-    "mediaPlayerPrivate",
     "metricsPrivate",
     "notifications",
     "power",

ui/file_manager/video_player/manifest.json

@@ -25,7 +25,6 @@
       "fileSystem": ["requestFileSystem", "write"]
     },
     "fullscreen",
-    "mediaPlayerPrivate",
     "metricsPrivate",
     "power",
     "storage",