Change classes that use FieldLoader to use read-only collections.

OpenRA.Mods.Common/Traits/Sound/SoundOnDamageTransition.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System.Collections.Immutable;
 using OpenRA.Primitives;
 using OpenRA.Traits;
 
@@ -17,10 +18,10 @@ namespace OpenRA.Mods.Common.Traits.Sound
 	public class SoundOnDamageTransitionInfo : TraitInfo
 	{
 		[Desc("Play a random sound from this list when damaged.")]
-		public readonly string[] DamagedSounds = [];
+		public readonly ImmutableArray<string> DamagedSounds = [];
 
 		[Desc("Play a random sound from this list when destroyed.")]
-		public readonly string[] DestroyedSounds = [];
+		public readonly ImmutableArray<string> DestroyedSounds = [];
 
 		[Desc("DamageType(s) that trigger the sounds. Leave empty to always trigger a sound.")]
 		public readonly BitSet<DamageType> DamageTypes = default;