ensure no initializing shards during cluster cleanup (#39283) (#39480)

there are testing situations where newly created indices
are being wiped before they are fully initialized. This results
in an edge-case in the shard-locking strategy where an index
cannot be deleted.

This should fix that

Author: talevy

test/framework/src/main/java/org/elasticsearch/test/rest/ESRestTestCase.java

@@ -292,6 +292,7 @@ protected HttpHost buildHttpHost(String host, int port) {
     @After
     public final void cleanUpCluster() throws Exception {
         if (preserveClusterUponCompletion() == false) {
+            ensureNoInitializingShards();
             wipeCluster();
             waitForClusterStateUpdatesToFinish();
             logIfThereAreRunningTasks();
@@ -806,7 +807,7 @@ protected static void ensureNoInitializingShards() throws IOException {
         request.addParameter("wait_for_no_initializing_shards", "true");
         request.addParameter("timeout", "70s");
         request.addParameter("level", "shards");
-        client().performRequest(request);
+        adminClient().performRequest(request);
     }
 
     protected static void createIndex(String name, Settings settings) throws IOException {