Update Spring Cloud GCP to 5.12.2 and 6.2.2

See gh-1841

Signed-off-by: Min Zhu <zhumin@google.com>

Author: zhumin8

start-site/src/main/resources/application.yml

@@ -115,9 +115,9 @@ initializr:
         additionalBoms: [ spring-cloud ]
         mappings:
           - compatibilityRange: "[3.3.0,3.4.0-M1)"
-            version: 5.11.1
+            version: 5.12.2
           - compatibilityRange: "[3.4.0,3.5.0-M1)"
-            version: 6.2.1
+            version: 6.2.2
       spring-cloud-services:
         groupId: io.pivotal.spring.cloud
         artifactId: spring-cloud-services-dependencies