Does sitecore 9.0.2 supports Azure SQL managed instance(Azure SQL Paas) ?
Yes, Sitecore 9.0.2 does support Azure SQL. The KB page is a little outdated, but Sitecore 9.0.2 fully supports Azure SQL.
From their compatibility KB page: https://kb.sitecore.net/articles/777703
Sitecore supports Microsoft Azure SQL Database service for the following setups:
When running Sitecore XP 8.2 and later versions.
When running Sitecore XP 8.1 and earlier versions and deploying to Microsoft Azure using the Sitecore Azuremodule.
Sitecore does not support using Azure SQL Databases in the following situations:
When using Email Experience Manager module prior to Sitecore 9.0.1 (not mentioned in link)
When running any configuration that is not mentioned in the supported list.