{OperationalInsight} Ingestion value was removed from the DataSourceType enum (#19365)

The API version 2020-03-01-preview supported DataSourceType enum with 'Ingestion' as one of the valid values for log analytics linked storage account.
However, this value was removed in 2020-08-01 leading to 'Invalid value' error when storage accounts are linked to a workspace where the data source type is specified as Ingestion.

Author: navba-MSFT

specification/operationalinsights/resource-manager/Microsoft.OperationalInsights/stable/2020-08-01/LinkedStorageAccounts.json

@@ -206,6 +206,7 @@
             "CustomLogs",
             "AzureWatson",
             "Query",
+            "Ingestion",
             "Alerts"
           ],
           "x-ms-enum": {
@@ -263,6 +264,7 @@
         "CustomLogs",
         "AzureWatson",
         "Query",
+        "Ingestion",
         "Alerts"
       ],
       "x-ms-enum": {