Throw exception for unsupported values type in Alias (#124737)

After creating index with alias using the following request

```
PUT test-index
{
  "aliases": {
    "alias1": {
      "is_write_index": "true"
    }
  }
}
```

we got the following result for get index request:

```
{
  "test-index" : {
    "aliases" : {
      "alias1" : { }
    },
    "mappings" : { },
    "settings" : {   
      ...
    }
  }
}
```

The `is_write_index` field is missing because string boolean value is
not supported for this filed and `no warning message showed`, which will
mislead the users. In #120453 I open a PR to let the createIndex API
support string boolean values for `is_write_index` field, but @dakrone
think it's better to be strict about boolean values. So I open this PR
to let the Alias class throw exception for the unsupport value type to
avoid the slience swallowing of this case.

Author: mushao999

docs/changelog/124737.yaml

@@ -0,0 +1,5 @@
+pr: 124737
+summary: Throw exception for unsupported values type in Alias
+area: Indices APIs
+type: enhancement
+issues: []

rest-api-spec/src/yamlRestTest/resources/rest-api-spec/test/indices.create/10_basic.yml

@@ -86,6 +86,38 @@
   - is_false: test_index.aliases.test_clias.index_routing
   - is_false: test_index.aliases.test_clias.search_routing
 
+---
+  "Throw exception for unsupported value type":
+    - requires:
+        cluster_features: [ "index.throw_exception_on_index_creation_if_unsupported_value_type_in_alias" ]
+        reason: "Throw exception on index creation if unsupported value type in alias"
+
+    - do:
+        catch: /Unsupported String type value \[true\] for field \[is_write_index\] in alias \[test_alias\]/
+        indices.create:
+          index: test_index
+          body:
+            mappings:
+              properties:
+                field:
+                  type: text
+            aliases:
+              test_alias:
+                is_write_index: "true"
+
+    - do:
+        catch: /Unsupported boolean type value \[true\] for field \[routing\] in alias \[test_alias\]/
+        indices.create:
+          index: test_index
+          body:
+            mappings:
+              properties:
+                field:
+                  type: text
+            aliases:
+              test_alias:
+                routing: true
+
 ---
 "Create index with write aliases":
 

server/src/main/java/org/elasticsearch/action/admin/indices/alias/Alias.java

@@ -257,12 +257,32 @@ public static Alias fromXContent(XContentParser parser) throws IOException {
                     alias.indexRouting(parser.text());
                 } else if (SEARCH_ROUTING.match(currentFieldName, parser.getDeprecationHandler())) {
                     alias.searchRouting(parser.text());
+                } else {
+                    throw new IllegalArgumentException(
+                        "Unsupported String type value ["
+                            + parser.text()
+                            + "] for field ["
+                            + currentFieldName
+                            + "] in alias ["
+                            + alias.name
+                            + "]"
+                    );
                 }
             } else if (token == XContentParser.Token.VALUE_BOOLEAN) {
                 if (IS_WRITE_INDEX.match(currentFieldName, parser.getDeprecationHandler())) {
                     alias.writeIndex(parser.booleanValue());
                 } else if (IS_HIDDEN.match(currentFieldName, parser.getDeprecationHandler())) {
                     alias.isHidden(parser.booleanValue());
+                } else {
+                    throw new IllegalArgumentException(
+                        "Unsupported boolean type value ["
+                            + parser.text()
+                            + "] for field ["
+                            + currentFieldName
+                            + "] in alias ["
+                            + alias.name
+                            + "]"
+                    );
                 }
             } else {
                 throw new IllegalArgumentException("Unknown token [" + token + "] in alias [" + alias.name + "]");

server/src/main/java/org/elasticsearch/index/IndexFeatures.java

@@ -25,8 +25,16 @@ public Set<NodeFeature> getFeatures() {
 
     private static final NodeFeature SYNONYMS_SET_LENIENT_ON_NON_EXISTING = new NodeFeature("index.synonyms_set_lenient_on_non_existing");
 
+    private static final NodeFeature THROW_EXCEPTION_ON_INDEX_CREATION_IF_UNSUPPORTED_VALUE_TYPE_IN_ALIAS = new NodeFeature(
+        "index.throw_exception_on_index_creation_if_unsupported_value_type_in_alias"
+    );
+
     @Override
     public Set<NodeFeature> getTestFeatures() {
-        return Set.of(LOGSDB_NO_HOST_NAME_FIELD, SYNONYMS_SET_LENIENT_ON_NON_EXISTING);
+        return Set.of(
+            LOGSDB_NO_HOST_NAME_FIELD,
+            SYNONYMS_SET_LENIENT_ON_NON_EXISTING,
+            THROW_EXCEPTION_ON_INDEX_CREATION_IF_UNSUPPORTED_VALUE_TYPE_IN_ALIAS
+        );
     }
 }