test: Enable sass compiler for bazel integration test (#19357)

integration/bazel/src/hello-world/BUILD.bazel

@@ -1,10 +1,15 @@
 package(default_visibility = ["//visibility:public"])
 load("@angular//:index.bzl", "ng_module")
+load("@io_bazel_rules_sass//sass:sass.bzl", "sass_binary")
+
+sass_binary(
+    name = "hello-world-styles",
+    src = "hello-world.component.scss",
+)
 
 ng_module(
     name = "hello-world",
     srcs = glob(["*.ts"]),
     tsconfig = "//src:tsconfig.json",
-    # TODO(alexeagle): re-enable
-    # assets = [":styles"],
+    assets = [":hello-world-styles.css"],
 )

integration/bazel/src/hello-world/hello-world.component.scss

@@ -0,0 +1,5 @@
+$example-red: #ff0000;
+
+h1 {
+  color: $example-red;
+}

integration/bazel/src/hello-world/hello-world.component.ts

@@ -8,8 +8,7 @@ import {Component, NgModule} from '@angular/core';
     <input type="text" [value]="name" (input)="name = $event.target.value"/>
   `,
   // TODO: might be better to point to .scss so this looks valid at design-time
-  // TODO(alexeagle): re-enable SASS
-  // styleUrls: ['./styles.css']
+  styleUrls: ['./hello-world-styles.css'],
 })
 export class HelloWorldComponent {
   name: string = 'world';