MTDSA-22473: Security Review and PR cleanup (#125)

* MTDSA-22473: Removes unused trait from AppConfig.

* MTDSA-22473: Removes HMRCDocumentationController and adapts DocumentationController accordingly.

app/config/AppConfig.scala

@@ -85,11 +85,6 @@ class AppConfigImpl @Inject() (config: ServicesConfig, configuration: Configurat
   def endpointsEnabled(version: Version): Boolean  = config.getBoolean(s"api.${version.name}.endpoints.enabled")
 }
 
-trait FixedConfig {
-  // Minimum tax year for MTD
-  val minimumTaxYear = 2018
-}
-
 case class ConfidenceLevelConfig(confidenceLevel: ConfidenceLevel, definitionEnabled: Boolean, authValidationEnabled: Boolean)
 
 object ConfidenceLevelConfig {

app/config/DocumentationController.scala

@@ -18,20 +18,18 @@ package config
 
 import controllers.Assets
 import definition.ApiDefinitionFactory
-import play.api.http.HttpErrorHandler
 import play.api.libs.json.Json
 import play.api.mvc.{Action, AnyContent, ControllerComponents}
+import uk.gov.hmrc.play.bootstrap.backend.controller.BackendController
 
 import javax.inject.{Inject, Singleton}
 
 @Singleton
 class DocumentationController @Inject() (selfAssessmentApiDefinition: ApiDefinitionFactory,
                                          cc: ControllerComponents,
-                                         assets: Assets,
-                                         errorHandler: HttpErrorHandler)
-    extends HmrcDocumentationController(cc, assets, errorHandler) {
+                                         assets: Assets) extends BackendController(cc) {
 
-  override def definition(): Action[AnyContent] = Action {
+  def definition(): Action[AnyContent] = Action {
     Ok(Json.toJson(selfAssessmentApiDefinition.definition))
   }