Hi @Amol ,
You can add solutions like "container monitoring solution" to log analytics workspace using Az PS cmdlet New-AzMonitorLogAnalyticsSolution or az monitor log-analytics solution create Az CLI command but AFAIK currently there is no REST API support for the same Az PS cmdlet or Az CLI command. For more information with regards to it, you may refer this / this Azure documentation.
However, as we don't see any official documentation that mentions about REST API support for the same so I am reaching out to our internal product team to confirm the same and see if we have any ETA on API support and also see if we have any workaround for this until we have the API support. Will keep you updated as I hear more information.