Samples cleanup

- Modifying dependencies to starter-web with tomcat exclusion plus
  alternative servlet container instead of manual dependency on
  spring-webmvc as it is the preferrable way to use alternative servlet
  container
- Previously RestTemplate with ssl was configured manually in tests - now
  it rellies on autoconfiguration - changed this for multi-connector test
  and added test to ensure that ssl autoconfiguration is working
- Most samples with alterntative servlet containers used some kind of
  service reading property and returning default since it wasn't
  configured - removed it, since it is not specific to using alternative
  servlet containers.

See gh-10548

spring-boot-samples/spring-boot-sample-tomcat-ssl/pom.xml

@@ -18,19 +18,7 @@
 		<!-- Compile -->
 		<dependency>
 			<groupId>org.springframework.boot</groupId>
-			<artifactId>spring-boot-starter</artifactId>
-		</dependency>
-		<dependency>
-			<groupId>org.springframework.boot</groupId>
-			<artifactId>spring-boot-starter-tomcat</artifactId>
-		</dependency>
-		<dependency>
-			<groupId>org.springframework</groupId>
-			<artifactId>spring-webmvc</artifactId>
-		</dependency>
-		<dependency>
-			<groupId>org.apache.httpcomponents</groupId>
-			<artifactId>httpclient</artifactId>
+			<artifactId>spring-boot-starter-web</artifactId>
 		</dependency>
 		<!-- Test -->
 		<dependency>
@@ -39,8 +27,9 @@
 			<scope>test</scope>
 		</dependency>
 		<dependency>
-			<groupId>org.yaml</groupId>
-			<artifactId>snakeyaml</artifactId>
+			<groupId>org.apache.httpcomponents</groupId>
+			<artifactId>httpclient</artifactId>
+			<scope>test</scope>
 		</dependency>
 	</dependencies>
 	<build>