baremetal_database_db_system mandating hostname,domain database, dbhome even they are Optional

[jmajumde]

Description of the bug:

As per https://github.com/oracle/terraform-provider-baremetal/blob/master/docs/resources/database/db_system.md

domain - (Optional) A domain name to assign to the DB System.
hostname - (Optional) The host name to assign to the DB Node.

db_home - (Optional) Create DBHome details.

But provider is mandating these for the first time.

A self-contained terraform file that reproduces the issue:

• baremetal_database_db_system.jmtfenv4-dbsystem: 1 error(s) occurred:

• baremetal_database_db_system.jmtfenv4-dbsystem: Code: InvalidParameter; OPC Request ID: /B1519E29C6DB445989A8A6C5D07799C7/3D7511B417FF426C8D5F69880E2BF9AB; Message: hostname cannot be null.

After I mention the hostname now it complains for domain

• baremetal_database_db_system.jmtfenv4-dbsystem: 1 error(s) occurred:

• baremetal_database_db_system.jmtfenv4-dbsystem: Code: InvalidParameter; OPC Request ID: /B92BCA77C08F4DBBBB8033E0C51740FE/B1A6DD20A54F494293AE78C0A58338EA; Message: subnet domain name cannot be null.

After I mention the domain now it complains for db_home, db_version etc

error(s) occurred:

• baremetal_database_db_system.jmtfenv4-dbsystem: 1 error(s) occurred:

• baremetal_database_db_system.jmtfenv4-dbsystem: Code: InvalidParameter; OPC Request ID: /17799D0B377F4F69BFBD002458584BB0/0B7ADBC9D7E444349800BBC55FE0648A; Message: The database version cannot be an empty string.

[craigcarl-oracle]

Fix will ship this week.

[codycushing]

These params are actually required, docs have been updated