Frozen autoscaling should not use local storage

The reactive decider no longer applies to the frozen tier, since it
could grossly over-estimate the amount of storage for unassigned frozen
shards.

Relates elastic#71042

x-pack/plugin/autoscaling/src/internalClusterTest/java/org/elasticsearch/xpack/autoscaling/storage/ReactiveStorageIT.java

@@ -191,7 +191,7 @@ public void testScaleFromEmptyLegacy() {
     }
 
     /**
-     * Verify that the list of roles includes all data roles to ensure we consider adding future data roles.
+     * Verify that the list of roles includes all data roles except frozen to ensure we consider adding future data roles.
      */
     public void testRoles() {
         // this has to be an integration test to ensure roles are available.
@@ -204,7 +204,9 @@ public void testRoles() {
         assertThat(
             service.roles().stream().sorted().collect(Collectors.toList()),
             Matchers.equalTo(
-                DiscoveryNode.getPossibleRoles().stream().filter(DiscoveryNodeRole::canContainData).sorted().collect(Collectors.toList())
+                DiscoveryNode.getPossibleRoles().stream().filter(DiscoveryNodeRole::canContainData)
+                    .filter(r -> r != DiscoveryNodeRole.DATA_FROZEN_NODE_ROLE)
+                    .sorted().collect(Collectors.toList())
             )
         );
     }

x-pack/plugin/autoscaling/src/main/java/org/elasticsearch/xpack/autoscaling/storage/ReactiveStorageDeciderService.java

@@ -90,8 +90,7 @@ public List<DiscoveryNodeRole> roles() {
             DiscoveryNodeRole.DATA_CONTENT_NODE_ROLE,
             DiscoveryNodeRole.DATA_HOT_NODE_ROLE,
             DiscoveryNodeRole.DATA_WARM_NODE_ROLE,
-            DiscoveryNodeRole.DATA_COLD_NODE_ROLE,
-            DiscoveryNodeRole.DATA_FROZEN_NODE_ROLE
+            DiscoveryNodeRole.DATA_COLD_NODE_ROLE
         );
     }