message: [datasources] Fix, Prevent gamma user's from accessing save datasources
diff: @@ -105,6 +105,7 @@ class SupersetSecurityManager(SecurityManager):
  "DruidColumnInlineView",
  "DruidDatasourceModelView",
  "DruidMetricInlineView",
  + "Datasource",
  } | READ_ONLY_MODEL_VIEWS
  ADMIN_ONLY_VIEW_MENUS = {
  @@ -131,7 +132,7 @@ class SupersetSecurityManager(SecurityManager):
  "all_query_access",
  }
  - READ_ONLY_PERMISSION = {"can_show", "can_list"}
  + READ_ONLY_PERMISSION = {"can_show", "can_list", "can_get", "can_external_metadata"}
  ALPHA_ONLY_PERMISSIONS = {
  "muldelete",
  