App Transport Security has blocked a cleartext HTTP (http://) resource load since it is insecure

I couldn't find any documentation on how to use these methods, but did get it working through trial and error.

Hopefully this will help others in the future.

 public class AllowHTTPSupportCodes : MonoBehaviour 
 {
     [PostProcessBuild]
     public static void OnPostprocessBuild(BuildTarget buildTarget, string pathToBuiltProject) 
     {
         if (buildTarget == BuildTarget.iOS) {
 
             // Get plist
             string plistPath = pathToBuiltProject + "/Info.plist";
             PlistDocument plist = new PlistDocument();
             plist.ReadFromString(File.ReadAllText(plistPath));
 
             PlistElementDict allowsDict = plist.root.CreateDict("NSAppTransportSecurity");
 
             allowsDict.SetBoolean("NSAllowsArbitraryLoads", true);
 
             PlistElementDict exceptionsDict = allowsDict.CreateDict("NSExceptionDomains");
 
             PlistElementDict domainDict = exceptionsDict.CreateDict("amazonaws.com");
 
             domainDict.SetBoolean("NSExceptionAllowsInsecureHTTPLoads", true);
             domainDict.SetBoolean("NSIncludesSubdomains", true);
 
             // Write to file
             File.WriteAllText(plistPath, plist.WriteToString());
         }
     }
 }