Downgraded the version of ManagedInstances to generate .Net SDK for s…

…ql/resource manager (Azure#29316)

* Downgraded the version of ManagedInstances and DistributedAvailabilityGroups Api due to .Net Sdk build failures caused by error : MembersMustExist  in these API's

* restored the version of ManagedInstance Api as previous

* Update the version of ManagedInstance APi to previous version 22-08-01 as having build erros while building .net sdk with error 'implementation but it does exist in the contract.'

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Co-authored-by: Ji Wang <jiwang5@microsoft.com>

specification/sql/resource-manager/readme.md

@@ -1415,6 +1415,7 @@ input-file:
 - ./Microsoft.Sql/preview/2023-02-01-preview/Databases.json
 - ./Microsoft.Sql/preview/2022-08-01-preview/ElasticPools.json
 - ./Microsoft.Sql/preview/2022-08-01-preview/ManagedDatabases.json
+- ./Microsoft.Sql/preview/2022-08-01-preview/ManagedInstances.json
 - ./Microsoft.Sql/preview/2022-08-01-preview/ManagedLedgerDigestUploads.json
 - ./Microsoft.Sql/preview/2022-08-01-preview/RecoverableDatabases.json
 - ./Microsoft.Sql/preview/2022-08-01-preview/RestorableDroppedDatabases.json
@@ -1439,7 +1440,6 @@ input-file:
 - ./Microsoft.Sql/preview/2023-05-01-preview/InstancePools.json
 - ./Microsoft.Sql/preview/2023-05-01-preview/LongTermRetentionBackups.json
 - ./Microsoft.Sql/preview/2023-05-01-preview/LongTermRetentionPolicies.json
-- ./Microsoft.Sql/preview/2023-05-01-preview/ManagedInstances.json
 - ./Microsoft.Sql/preview/2023-05-01-preview/Servers.json
 - ./Microsoft.Sql/preview/2023-05-01-preview/ReplicationLinks.json