[video_player] Update iOS README section (#4688)

Removes the suggestion to just use the strongly-discouraged-by-Apple `NSAllowsArbitraryLoads`, and instead links to Apple's docs about the various options.

This removes the example entirely since there's no one-size-fits-all case; some clients would just need `NSExceptionDomains` (this seems likely to be the more common case?), others `NSAllowsArbitraryLoadsForMedia`, others `NSAllowsArbitraryLoadsForMedia`+` NSAllowsArbitraryLoads` (to support iOS 9). Given that the narrowest option that works for someone is the best option, having them actually research the options is the best thing to steer people toward, even if that's not as simple as "copy and paste the following".

Also opportunistically removes a couple of obsolete items:
- An incorrect note that `android.permission.INTERNET` is likely already present in the
  main Android manifest file; it was made debug-only a while ago.
- An old note about web version compatibility; we only support Flutter 2+ now anyway.
diff --git a/packages/video_player/video_player/CHANGELOG.md b/packages/video_player/video_player/CHANGELOG.md
index dfd4a31..b7225a8 100644
--- a/packages/video_player/video_player/CHANGELOG.md
+++ b/packages/video_player/video_player/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 2.2.15
+
+* Updates README discussion of permissions.
+
 ## 2.2.14
 
 * Removes KVO observer on AVPlayerItem on iOS.
diff --git a/packages/video_player/video_player/README.md b/packages/video_player/video_player/README.md
index d5e7528..84b3ae7 100644
--- a/packages/video_player/video_player/README.md
+++ b/packages/video_player/video_player/README.md
@@ -12,32 +12,23 @@
 
 ### iOS
 
-This plugin requires iOS 9.0 or higher. Add the following entry to your _Info.plist_ file, located in `<project root>/ios/Runner/Info.plist`:
-
-```xml
-<key>NSAppTransportSecurity</key>
-<dict>
-  <key>NSAllowsArbitraryLoads</key>
-  <true/>
-</dict>
-```
-
-This entry allows your app to access video files by URL.
+If you need to access videos using `http` (rather than `https`) URLs, you will need to add
+the appropriate `NSAppTransportSecurity` permissions to your app's _Info.plist_ file, located
+in `<project root>/ios/Runner/Info.plist`. See
+[Apple's documentation](https://developer.apple.com/documentation/bundleresources/information_property_list/nsapptransportsecurity)
+to determine the right combination of entries for your use case and supported iOS versions.
 
 ### Android
 
-Ensure the following permission is present in your Android Manifest file, located in `<project root>/android/app/src/main/AndroidManifest.xml`:
+If you are using network-based videos, ensure that the following permission is present in your
+Android Manifest file, located in `<project root>/android/app/src/main/AndroidManifest.xml`:
 
 ```xml
 <uses-permission android:name="android.permission.INTERNET"/>
 ```
 
-The Flutter project template adds it, so it may already be there.
-
 ### Web
 
-This plugin compiles for the web platform since version `0.10.5`, in recent enough versions of Flutter (`>=1.12.13+hotfix.4`).
-
 > The Web platform does **not** suppport `dart:io`, so avoid using the `VideoPlayerController.file` constructor for the plugin. Using the constructor attempts to create a `VideoPlayerController.file` that will throw an `UnimplementedError`.
 
 Different web browsers may have different video-playback capabilities (supported formats, autoplay...). Check [package:video_player_web](https://pub.dev/packages/video_player_web) for more web-specific information.
diff --git a/packages/video_player/video_player/pubspec.yaml b/packages/video_player/video_player/pubspec.yaml
index 0260b84..24aef06 100644
--- a/packages/video_player/video_player/pubspec.yaml
+++ b/packages/video_player/video_player/pubspec.yaml
@@ -3,7 +3,7 @@
   widgets on Android, iOS, and web.
 repository: https://github.com/flutter/plugins/tree/master/packages/video_player/video_player
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+video_player%22
-version: 2.2.14
+version: 2.2.15
 
 environment:
   sdk: ">=2.14.0 <3.0.0"