[ReleasePR monitor] [Hub Generated] Review request for Microsoft.Insights to add version stable/2018-03-01 (#1908)

Create to sync Azure/azure-rest-api-specs#15749
[ReCreate this PR](https://github.com/azure-resource-manager-schemas/compare/main...AzureSDKAutomation:sdkAuto/monitor?expand=1)

Author: msftbot[bot]

schemas/2018-03-01/Microsoft.Insights.json

@@ -819,7 +819,6 @@
               "type": "string",
               "enum": [
                 "Equals",
-                "NotEquals",
                 "GreaterThan",
                 "GreaterThanOrEqual",
                 "LessThan",