Bump gradle in /examples/fabric-contract-example-as-service (#441)

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

examples/fabric-contract-example-as-service/Dockerfile

@@ -4,7 +4,7 @@
 # Example multi-stage dockerfile for Java Chaincode
 
 # the first stage 
-FROM gradle:8-jdk21 AS gradle_build
+FROM gradle:9-jdk21 AS gradle_build
 
 # copy the build.gradle and src code to the container
 COPY src/ src/