Add missing @ConditionalOnMissingBean annotations

Seems to be necessary as a result of the changes related to spring-projects/spring-boot#13609

Author: tomcruise81

Diff for: spring-security-oauth2-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/security/oauth2/resource/ResourceServerTokenServicesConfiguration.java

@@ -277,6 +277,7 @@ public TokenStore jwtTokenStore() {
 		}
 
 		@Bean
+		@ConditionalOnMissingBean(JwtAccessTokenConverter.class)
 		public JwtAccessTokenConverter jwtTokenEnhancer() {
 			JwtAccessTokenConverter converter = new JwtAccessTokenConverter();
 			String keyValue = this.resource.getJwt().getKeyValue();
@@ -356,6 +357,7 @@ public TokenStore tokenStore() {
 		}
 
 		@Bean
+		@ConditionalOnMissingBean(JwtAccessTokenConverter.class)
 		public JwtAccessTokenConverter accessTokenConverter() {
 			Assert.notNull(this.resource.getJwt().getKeyStore(),
 					"keyStore cannot be null");

Diff for: spring-security-oauth2-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/security/oauth2/resource/ResourceServerTokenServicesConfigurationTests.java

@@ -278,6 +278,30 @@ public void jwtTokenStoreShouldBeConditionalOnMissingBean() throws Exception {
 		assertThat(this.context.getBeansOfType(JwtTokenStore.class)).hasSize(1);
 	}
 
+	@Test
+	public void jwtAccessTokenConverterForKeyValueShouldBeConditionalOnMissingBean()
+			throws Exception {
+		TestPropertyValues.of("security.oauth2.resource.jwt.keyValue=" + PUBLIC_KEY)
+				.applyTo(this.environment);
+		this.context = new SpringApplicationBuilder(JwtTokenStoreConfiguration.class,
+				ResourceConfiguration.class).environment(this.environment)
+						.web(WebApplicationType.NONE).run();
+		assertThat(this.context.getBeansOfType(JwtAccessTokenConverter.class)).hasSize(1);
+	}
+
+	@Test
+	public void jwtAccessTokenConverterForKeyStoreShouldBeConditionalOnMissingBean()
+			throws Exception {
+		TestPropertyValues.of("security.oauth2.resource.jwt.key-store=classpath:"
+				+ "org/springframework/boot/autoconfigure/security/oauth2/resource/keystore.jks",
+				"security.oauth2.resource.jwt.key-store-password=changeme",
+				"security.oauth2.resource.jwt.key-alias=jwt").applyTo(this.environment);
+		this.context = new SpringApplicationBuilder(JwtTokenStoreConfiguration.class,
+				ResourceConfiguration.class).environment(this.environment)
+						.web(WebApplicationType.NONE).run();
+		assertThat(this.context.getBeansOfType(JwtAccessTokenConverter.class)).hasSize(1);
+	}
+
 	@Test
 	public void configureWhenKeyStoreIsProvidedThenExposesJwtTokenStore() {
 		TestPropertyValues.of("security.oauth2.resource.jwt.key-store=classpath:"