Add retry count and is retryable to ILM explain (#4391)

Relates: #4341, elastic/elasticsearch#48256

This commit adds FailedStepRetryCount and IsAutoRetryableError
properties to ILM explain, applicable if a step fails.

(cherry picked from commit 4dc0e83)

Author: russcam

src/Nest/XPack/Ilm/ExplainLifecycle/ExplainLifecycleResponse.cs

@@ -24,12 +24,25 @@ public class LifecycleExplain
 		[JsonFormatter(typeof(DateTimeOffsetEpochMillisecondsFormatter))]
 		public DateTimeOffset ActionTime { get; internal set; }
 
+		/// <summary>
+		///	Indicates if retrying a failed step can overcome the error.
+		/// If this is true, the failed step will be retried automatically.
+		/// </summary>
+		[DataMember(Name = "is_auto_retryable_error")]
+		public bool? IsAutoRetryableError { get; internal set; }
+
 		/// <summary>
 		/// The step that caused the error, if applicable.
 		/// </summary>
 		[DataMember(Name = "failed_step")]
 		public string FailedStep { get; internal set; }
 
+		/// <summary>
+		/// Number of attempted automatic retries to execute the failed step, if applicable.
+		/// </summary>
+		[DataMember(Name = "failed_step_retry_count")]
+		public int? FailedStepRetryCount { get; internal set; }
+
 		[DataMember(Name = "index")]
 		public IndexName Index { get; internal set; }