fix bug that prevent index.mapping settings to be propagated into component templates from default settings (#157289)

## Summary

If you have a setting like `index.mapping.ignore_malformed`, in the
default settings, that is currently not propagated when a new component
template is built in the function `buildComponentTemplates` in Fleet


### Checklist

Delete any items that are not applicable to this PR.

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guidelines](https://elastic.github.io/eui/#/guidelines/writing), uses
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support](https://github.com/elastic/kibana/blob/main/packages/kbn-i18n/README.md)
- [ ]
[Documentation](https://www.elastic.co/guide/en/kibana/master/development-documentation.html)
was added for features that require explanation or tutorials
- [ ] [Unit or functional
tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)
were updated or added to match the most common scenarios
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---------

Co-authored-by: Kyle Pollich <kyle.pollich@elastic.co>

x-pack/plugins/fleet/common/types/models/epm.ts

@@ -581,7 +581,7 @@ export interface TemplateMapEntry {
         mappings: NonNullable<RegistryElasticsearch['index_template.mappings']>;
       }
     | {
-        settings: NonNullable<RegistryElasticsearch['index_template.settings']> | object;
+        settings: NonNullable<RegistryElasticsearch['index_template.settings']>;
       };
 }
 

x-pack/plugins/fleet/server/services/epm/elasticsearch/template/install.test.ts

@@ -286,4 +286,45 @@ describe('EPM index template install', () => {
       index: { mode: 'time_series' },
     });
   });
+
+  it('test prepareTemplate to set ignore_malformed in settings', () => {
+    const dataStream = {
+      type: 'logs',
+      dataset: 'package.dataset',
+      title: 'test data stream',
+      release: 'experimental',
+      package: 'package',
+      path: 'path',
+      ingest_pipeline: 'default',
+      elasticsearch: {
+        'index_template.settings': {
+          index: {
+            mapping: {
+              ignored_malformed: true,
+            },
+          },
+        },
+      },
+    } as RegistryDataStream;
+
+    const pkg = {
+      name: 'package',
+      version: '0.0.1',
+    };
+
+    const { componentTemplates } = prepareTemplate({
+      pkg,
+      dataStream,
+    });
+
+    const packageTemplate = componentTemplates['logs-package.dataset@package'].template;
+
+    if (!('settings' in packageTemplate)) {
+      throw new Error('no mappings on package template');
+    }
+
+    expect(packageTemplate.settings?.index?.mapping).toEqual(
+      expect.objectContaining({ ignored_malformed: true })
+    );
+  });
 });

x-pack/plugins/fleet/server/services/epm/elasticsearch/template/install.ts

@@ -322,9 +322,9 @@ export function buildComponentTemplates(params: {
           ...templateSettings.index,
           ...(pipelineName ? { default_pipeline: pipelineName } : {}),
           mapping: {
-            ...templateSettings?.mapping,
+            ...templateSettings.index?.mapping,
             total_fields: {
-              ...templateSettings?.mapping?.total_fields,
+              ...templateSettings.index?.mapping?.total_fields,
               limit: '10000',
             },
           },