Fix TimeSeriesDataStreamsIT.testShrinkActionInPolicyWithoutHotPhase (elastic#123153) (elastic#123736)

This test was muted, got fixed, and then was muted again but the issue
wasn't reopened (by accident it seems). Since that was 4 years ago, I'm
going to unmute this test and if it's still an issue, the new test
automation will open a new issue for it using the current muting
mechanism.

Relates elastic#70595

(cherry picked from commit 4b31293)

Author: nielsbauman

x-pack/plugin/ilm/qa/multi-node/src/javaRestTest/java/org/elasticsearch/xpack/TimeSeriesRestDriver.java

@@ -455,6 +455,9 @@ public static String waitAndGetShrinkIndexName(RestClient client, String origina
                     "GET",
                     SHRUNKEN_INDEX_PREFIX + "*" + originalIndex + "," + originalIndex + "/_ilm/explain"
                 );
+                // Sometimes, the original index might already have been deleted, so we need to ignore unavailable (concrete) indices.
+                explainRequest.addParameter("ignore_unavailable", Boolean.toString(true));
+                explainRequest.addParameter("expand_wildcards", "open,hidden");
                 explainRequest.addParameter("only_errors", Boolean.toString(false));
                 explainRequest.addParameter("only_managed", Boolean.toString(false));
                 Response response = client.performRequest(explainRequest);

x-pack/plugin/ilm/qa/multi-node/src/javaRestTest/java/org/elasticsearch/xpack/ilm/TimeSeriesDataStreamsIT.java

@@ -120,7 +120,6 @@ public void testRolloverIsSkippedOnManualDataStreamRollover() throws Exception {
         );
     }
 
-    @AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/issues/70595")
     public void testShrinkActionInPolicyWithoutHotPhase() throws Exception {
         createNewSingletonPolicy(client(), policyName, "warm", new ShrinkAction(1, null, false));
         createComposableTemplate(client(), template, dataStream + "*", getTemplate(policyName));