fix(elasticsearch): make indexNameMapping in IndexConventionImpl threadsafe

[iprentic]

There was a ConcurrentModificationException seen in this class:

2023-03-05 03:46:06,210 [Thread-134] ERROR c.l.d.g.e.DataHubDataFetcherExceptionHandler:21 - Failed to execute DataFetcher
java.util.concurrent.CompletionException: java.lang.RuntimeException: Failed to list Views
at java.base/java.util.concurrent.CompletableFuture.encodeThrowable(CompletableFuture.java:314)
at java.base/java.util.concurrent.CompletableFuture.completeThrowable(CompletableFuture.java:319)
at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1702)
at java.base/java.lang.Thread.run(Thread.java:829)
Caused by: java.lang.RuntimeException: Failed to list Views
at com.linkedin.datahub.graphql.resolvers.view.ListMyViewsResolver.lambda$get$0(ListMyViewsResolver.java:91)
at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1700)
... 1 common frames omitted
Caused by: java.util.ConcurrentModificationException: null
at java.base/java.util.HashMap.computeIfAbsent(HashMap.java:1135)
at com.linkedin.metadata.utils.elasticsearch.IndexConventionImpl.getIndexName(IndexConventionImpl.java:57)
at com.linkedin.metadata.utils.elasticsearch.IndexConventionImpl.getEntityIndexName(IndexConventionImpl.java:63)
at com.linkedin.metadata.utils.elasticsearch.IndexConventionImpl.getIndexName(IndexConventionImpl.java:51)
at com.linkedin.metadata.search.elasticsearch.query.ESSearchDAO.search(ESSearchDAO.java:151)
at com.linkedin.metadata.search.elasticsearch.ElasticSearchService.fullTextSearch(ElasticSearchService.java:112)
at com.linkedin.metadata.client.JavaEntityClient.search(JavaEntityClient.java:311)
at com.linkedin.datahub.graphql.resolvers.view.ListMyViewsResolver.lambda$get$0(ListMyViewsResolver.java:71)

Make the data structure accessed to be a ConcurrentHashMap to handle multiple threads accessing at once.

Checklist

• The PR conforms to DataHub's Contributing Guideline (particularly Commit Message Format)
• Links to related issues (if applicable)
• Tests for the changes have been added/updated (if applicable)
• Docs related to the changes have been added/updated (if applicable). If a new feature has been added a Usage Guide has been added for the same.
• For any breaking change/potential downtime/deprecation/big changes an entry has been made in Updating DataHub

[david-leifker]

Make sure green before merge. Thanks!