[MAPS] Updating file upload privileges for maps test user (elastic#20…

…3992)

Clears deprecation warning triggered by maps file upload test.
The role used by the test user needs to now include `manage`

This should clear the `elastic/kibana-presentation` deprecation warnings
raised [here](elastic/kibana-team#1173)

(cherry picked from commit 6f38a4c)

x-pack/test/functional/config.base.js

@@ -401,7 +401,14 @@ export default async function ({ readConfigFile }) {
             indices: [
               {
                 names: ['*'],
-                privileges: ['create', 'read', 'view_index_metadata', 'monitor', 'create_index'],
+                privileges: [
+                  'create',
+                  'read',
+                  'view_index_metadata',
+                  'monitor',
+                  'create_index',
+                  'manage',
+                ],
               },
             ],
           },