adding app registration module

modules/app_registration/variables.tf

@@ -9,21 +9,23 @@ variable "id_token_issuance_enabled" {
 }
 
 variable "additional_resource_access" {
-  type = optional(list(object({
+  default = null
+  type = list(object({
     id = string
     type = string
-  })))
+  }))
 }
 
 variable "app_roles" {
-  type = optional(list(object({
+  default = null
+  type = list(object({
     allowed_member_types = list(string)
     description = string
     display_name = string
     enabled = bool
     id = string
     value = string
-  })))
+  }))
 }
 
 variable "app_reg_name" {
@@ -50,13 +52,14 @@ variable "destination" {
 }
 
 variable "federated_identity_credential" {
-  type = optional(object({
+  default = null
+  type = object({
     display_name = string
     description = string
     audiences = list(string)
     issuer = string
     subject = string
-  }))
+  })
 }
 
 variable "enable_identifier_uri" {
@@ -65,7 +68,8 @@ variable "enable_identifier_uri" {
 }
 
 variable "oauth2_permission_scopes" {
-  type = optional(list(object({
+  default = null
+  type = list(object({
     admin_consent_description = string
     admin_consent_display_name = string
     enabled = bool
@@ -74,14 +78,15 @@ variable "oauth2_permission_scopes" {
     user_consent_description = string
     user_consent_display_name = string
     value = string
-  })))
+  }))
 }
 
 variable "secret" {
-  type = optional(object({
+  default = null
+  type = object({
     display_name = string
     end_date = optional(string)
-  }))
+  })
 }
 
 variable "redirect_uris" {