[BUG] Deserializing weighted routing metadata

[anshu1106]

Describe the bug
Deserialization of weighted routing metadata is failing on process restart.

To Reproduce
Steps to reproduce the behavior:

1. For a multi az domain, set weighted routing weights using curl command curl -X PUT "localhost:9200/_cluster/routing/awareness/zone/weights" -H 'Content-Type: application/json' -d '{"us-east-1c" : "1", "us-east-1b":"0", "us-east-1d":"1"}'
2. Restart OS process on one of the data nodes
3. OS process restart fails with error :

[2022-10-03T13:29:58,597][ERROR][o.o.b.Bootstrap          ] [e8461910d5468d3abde9e564f23da1c3] Exception
OpenSearchParseException[failed to parse wrr metadata  [us-east-1d], expected object]
        at org.opensearch.cluster.metadata.WeightedRoundRobinRoutingMetadata.fromXContent(WeightedRoundRobinRoutingMetadata.java:110)
        at org.opensearch.common.xcontent.NamedXContentRegistry$Entry.lambda$new$0(NamedXContentRegistry.java:76)
        at org.opensearch.common.xcontent.NamedXContentRegistry.parseNamedObject(NamedXContentRegistry.java:166)
        at org.opensearch.common.xcontent.support.AbstractXContentParser.namedObject(AbstractXContentParser.java:435)
        at org.opensearch.cluster.metadata.Metadata$Builder.fromXContent(Metadata.java:1784)
        at org.opensearch.gateway.PersistedClusterStateService.lambda$loadOnDiskState$1(PersistedClusterStateService.java:443)
        at org.opensearch.gateway.PersistedClusterStateService.consumeFromType(PersistedClusterStateService.java:507)
        at org.opensearch.gateway.PersistedClusterStateService.loadOnDiskState(PersistedClusterStateService.java:442)
        at org.opensearch.gateway.PersistedClusterStateService.loadBestOnDiskState(PersistedClusterStateService.java:367)
        at org.opensearch.gateway.GatewayMetaState.start(GatewayMetaState.java:164)
        at org.opensearch.node.Node.start(Node.java:1087)
        at org.opensearch.bootstrap.Bootstrap.start(Bootstrap.java:339)
        at org.opensearch.bootstrap.Bootstrap.init(Bootstrap.java:421)
        at org.opensearch.bootstrap.OpenSearch.init(OpenSearch.java:179)
        at org.opensearch.bootstrap.OpenSearch.execute(OpenSearch.java:170)
        at org.opensearch.cli.EnvironmentAwareCommand.execute(EnvironmentAwareCommand.java:100)
        at org.opensearch.cli.Command.mainWithoutErrorHandling(Command.java:138)
        at org.opensearch.cli.Command.main(Command.java:101)
        at org.opensearch.bootstrap.OpenSearch.main(OpenSearch.java:136)
        at org.opensearch.bootstrap.OpenSearch.main(OpenSearch.java:102)
[2022-10-03T13:29:58,598][ERROR][o.o.b.OpenSearchUncaughtExceptionHandler] [e8461910d5468d3abde9e564f23da1c3] uncaught exception in thread [main]
OpenSearchParseException[failed to parse wrr metadata  [us-east-1d], expected object]
        at org.opensearch.cluster.metadata.WeightedRoundRobinRoutingMetadata.fromXContent(WeightedRoundRobinRoutingMetadata.java:110)
        at org.opensearch.common.xcontent.NamedXContentRegistry$Entry.lambda$new$0(NamedXContentRegistry.java:76)
        at org.opensearch.common.xcontent.NamedXContentRegistry.parseNamedObject(NamedXContentRegistry.java:166)
        at org.opensearch.common.xcontent.support.AbstractXContentParser.namedObject(AbstractXContentParser.java:435)
        at org.opensearch.cluster.metadata.Metadata$Builder.fromXContent(Metadata.java:1784)
        at org.opensearch.gateway.PersistedClusterStateService.lambda$loadOnDiskState$1(PersistedClusterStateService.java:443)
        at org.opensearch.gateway.PersistedClusterStateService.consumeFromType(PersistedClusterStateService.java:507)
        at org.opensearch.gateway.PersistedClusterStateService.loadOnDiskState(PersistedClusterStateService.java:442)
        at org.opensearch.gateway.PersistedClusterStateService.loadBestOnDiskState(PersistedClusterStateService.java:367)
        at org.opensearch.gateway.GatewayMetaState.start(GatewayMetaState.java:164)
        at org.opensearch.node.Node.start(Node.java:1087)
        at org.opensearch.bootstrap.Bootstrap.start(Bootstrap.java:339)
        at org.opensearch.bootstrap.Bootstrap.init(Bootstrap.java:421)
        at org.opensearch.bootstrap.OpenSearch.init(OpenSearch.java:179)
        at org.opensearch.bootstrap.OpenSearch.execute(OpenSearch.java:170)
        at org.opensearch.cli.EnvironmentAwareCommand.execute(EnvironmentAwareCommand.java:100)
        at org.opensearch.cli.Command.mainWithoutErrorHandling(Command.java:138)
        at org.opensearch.cli.Command.main(Command.java:101)
        at org.opensearch.bootstrap.OpenSearch.main(OpenSearch.java:136)
        at org.opensearch.bootstrap.OpenSearch.main(OpenSearch.java:102)

Expected behavior
Process restart shouldn't fail.

Host/Environment (please complete the following information):

• OS: macOS 12.5.1