the cold-hot separation feature is still
under development. And seems there are some unsolved feature remains.
So I add a fe config enable_storage_policy, and default is false, to disable the creation and usage of storage policy by default.
So that user can aware that he is using an experimental feature on his own, and it will not be released formally in v1.2.0.
Disable storage policy by default, user can not use or create storage policy. Configured by enable_storage_policy.
Remove property remote_storage_policy, it is duplicate with storage_policy
Change the persist field in DataProperty.java.
And remove remoteCooldownTime from DataProperty, because it can be got from StoragePolicy.
ca90253b09