Set backward compatible defaults

Author: aaron-lane

modules/postgresql/variables.tf

@@ -130,9 +130,9 @@ variable "backup_configuration" {
     start_time         = string
   })
   default = {
-    binary_log_enabled = false
-    enabled            = false
-    start_time         = ""
+    binary_log_enabled = null
+    enabled            = null
+    start_time         = null
   }
 }
 
@@ -258,7 +258,10 @@ variable "read_replica_configuration" {
     connect_retry_interval = number
     dump_file_path         = string
   })
-  default = null
+  default = {
+    connect_retry_interval = null
+    dump_file_path         = null
+  }
 }
 
 variable "read_replica_user_labels" {

modules/private_service_access/variables.tf

@@ -47,4 +47,3 @@ variable "labels" {
   type        = map(string)
   default     = {}
 }
-

modules/safer_mysql/variables.tf

@@ -137,9 +137,9 @@ variable "backup_configuration" {
     start_time         = string
   })
   default = {
-    binary_log_enabled = false
-    enabled            = false
-    start_time         = ""
+    binary_log_enabled = null
+    enabled            = null
+    start_time         = null
   }
 }
 
@@ -482,4 +482,3 @@ variable "delete_timeout" {
   type        = string
   default     = "15m"
 }
-