Update Spring Cloud GCP to 6.3.0 and 7.0.0

See gh-1867

Signed-off-by: Mridula <[email protected]>

Author: mpeddada1

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

@@ -111,7 +111,9 @@ initializr:
         additionalBoms: [ spring-cloud ]
         mappings:
           - compatibilityRange: "[3.4.0,3.5.0-M1)"
-            version: 6.2.3
+            version: 6.3.0
+          - compatibilityRange: "[3.5.0,3.6.0-M1)"
+            version: 7.0.0
       spring-cloud-services:
         groupId: io.pivotal.spring.cloud
         artifactId: spring-cloud-services-dependencies