Disable hypermedia in actuator endpoints by default

This change permanently removes links from the endpoints that return
arrays or collections, and also disables them in the rest of the
endpoints (except /actuator) by default.

Fixes gh-4616

spring-boot-samples/spring-boot-sample-hypermedia-gson/src/test/java/sample/hypermedia/gson/SampleHypermediaGsonApplicationTests.java

@@ -37,7 +37,7 @@ import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.
 @RunWith(SpringJUnit4ClassRunner.class)
 @SpringApplicationConfiguration(SampleHypermediaGsonApplication.class)
 @WebAppConfiguration
-@TestPropertySource(properties = "endpoints.health.sensitive: false")
+@TestPropertySource(properties = "endpoints.hypermedia.enabled: true")
 public class SampleHypermediaGsonApplicationTests {
 
 	@Autowired
@@ -61,9 +61,8 @@ public class SampleHypermediaGsonApplicationTests {
 	@Test
 	public void trace() throws Exception {
 		this.mockMvc.perform(get("/trace").accept(MediaType.APPLICATION_JSON))
-				.andExpect(status().isOk())
-				.andExpect(jsonPath("$.links[0].href").value("http://localhost/trace"))
-				.andExpect(jsonPath("$.content").isArray());
+				.andExpect(status().isOk()).andExpect(jsonPath("$.links").doesNotExist())
+				.andExpect(jsonPath("$").isArray());
 	}
 
 	@Test