[Fleet] Fix index patterns being recreated in default space, fix migr…

…ation version setting (elastic#164456)

Closes elastic#164243
Added a `typeMigrationVersion: '8.0.0'` to index patterns until
elastic#164454 is fixed.

Related to elastic#161969
Feedback from kibana core team, we should always set the migration
version fields, even if `migrationVersion` is not set.

It would be good to backport this to 8.9 too.

How to test locally:

- create a test space
- install system integration in test space
- restart kibana
- verify that the index patterns `logs-*`, `metrics-*` are still in test
space in Data Views UI

- [ ] [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

x-pack/plugins/fleet/server/services/epm/kibana/index_pattern/install.ts

@@ -18,6 +18,8 @@ export function getIndexPatternSavedObjects() {
   return indexPatternTypes.map((indexPatternType) => ({
     id: `${indexPatternType}-*`,
     type: INDEX_PATTERN_SAVED_OBJECT_TYPE,
+    // workaround until https://github.com/elastic/kibana/issues/164454 is fixed
+    typeMigrationVersion: '8.0.0',
     attributes: {
       title: `${indexPatternType}-*`,
       timeFieldName: '@timestamp',