fix(@schematics/angular): consecutive blank lines in routing.module.ts

Fixes: #18220
(cherry picked from commit d4198e5)

Author: sacgrover

packages/schematics/angular/module/files/__name@dasherize@if-flat__/__name@dasherize__-routing.module.ts.template

@@ -1,6 +1,6 @@
 import { NgModule } from '@angular/core';
-import { Routes, RouterModule } from '@angular/router';
-<% if (lazyRoute) { %>
+import { Routes, RouterModule } from '@angular/router';<% if (lazyRoute) { %>
+
 import { <%= classify(name) %>Component } from './<%= dasherize(name) %>.component';<% } %>
 
 const routes: Routes = [<% if (lazyRoute) { %>{ path: '', component: <%= classify(name) %>Component }<% } %>];