Disables Specification of Engine Version from RDS Instances

Minor updates are done for us automatically, so this makes terraform
want to roll them back.

To be tagged v2.1.13

base/jira/rds_jira/main.tf

@@ -22,13 +22,16 @@ module "jira_db" {
   name = "jira" # the DB name
 
   engine             = "postgres"
-  engine_version     = "11.8"
+  # engine_version     = "11.12" Leave this commented to use the latest from major_engine_version
   instance_class     = var.instance_type
   allocated_storage  = var.jira_rds_storage
   storage_encrypted  = true
   kms_key_id = module.jira_key.key_arn
   ca_cert_identifier = local.ca_cert_identifier
 
+  auto_minor_version_upgrade = true
+  allow_major_version_upgrade = false
+
   # NOTE: Do NOT use 'user' as the value for 'username' as it throws:
   # "Error creating DB Instance: InvalidParameterValue: MasterUsername
   # user cannot be used as it is a reserved word used by the engine"

base/rhsso/rds.tf

@@ -38,7 +38,7 @@ module "rhsso_db" {
   name = "rhsso" # the DB name
 
   engine             = "postgres"
-  engine_version     = "12.5"
+  #engine_version     = "12.7" # leave this disabled if you're doing auto_minor_version upgrades
   instance_class     = var.db_instance_type
   allocated_storage  = var.rds_storage
   storage_encrypted  = true
@@ -46,6 +46,9 @@ module "rhsso_db" {
   apply_immediately  = true # do not wait for maintenance window for changes
   ca_cert_identifier = local.ca_cert_identifier
 
+  auto_minor_version_upgrade = true
+  allow_major_version_upgrade = false
+
   # NOTE: Do NOT use 'user' as the value for 'username' as it throws:
   # "Error creating DB Instance: InvalidParameterValue: MasterUsername
   # user cannot be used as it is a reserved word used by the engine"