[AutoPR cost-management/resource-manager] Reports API moved from stable to preview version with addition of documentation of a couple of new APIs (#3145)

* Generated from 9f3607b94b9c3f9b6c2fa12ae00ed71a80d42699

Updated reports api documentation

* Generated from 41ff04d4ffb063505850fbecd4dd6061f4072f29

Undo remove of API from stable version

Author: AutorestCI