Allow for ID in create package policy request

E2E tests are failing because they include the ID field returned by the
package list endpoint. This just updates our request schema to accept an
ID, though we don't persist or deal with the ID anywhere.

Closes elastic#100897

x-pack/plugins/fleet/server/types/models/package_policy.ts

@@ -82,6 +82,7 @@ const PackagePolicyBaseSchema = {
 
 export const NewPackagePolicySchema = schema.object({
   ...PackagePolicyBaseSchema,
+  id: schema.maybe(schema.string()),
   force: schema.maybe(schema.boolean()),
 });