Add point in time recovery option in backend configuration (#50)

* Add point in time recovery option in backend coniguration

* Fix condition

modules/cloud-sql/main.tf

@@ -73,9 +73,10 @@ resource "google_sql_database_instance" "master" {
     }
 
     backup_configuration {
-      binary_log_enabled = local.actual_binary_log_enabled
-      enabled            = var.backup_enabled
-      start_time         = var.backup_start_time
+      binary_log_enabled             = local.actual_binary_log_enabled
+      enabled                        = var.backup_enabled
+      start_time                     = var.backup_start_time
+      point_in_time_recovery_enabled = local.is_postgres ? var.postgres_point_in_time_recovery_enabled : null
     }
 
     maintenance_window {

modules/cloud-sql/variables.tf

@@ -81,6 +81,12 @@ variable "backup_start_time" {
   default     = "04:00"
 }
 
+variable "postgres_point_in_time_recovery_enabled" {
+  description = "Will restart database if enabled after instance creation - only applicable to PostgreSQL"
+  type        = bool
+  default     = false
+}
+
 variable "mysql_binary_log_enabled" {
   description = "Set to false if you want to disable binary logs - only applicable to MySQL. Note, when using failover or read replicas, master and existing backups need to have binary_log_enabled=true set."
   type        = bool