Update Java app `adservice` to `openjdk:17-slim`

[mathieu-benoit]

trafficstars

Let's update the Java app adservice from openjdk:8-slim to openjdk:17-slim to get latest and greatest and decrease the amount of CVEs.

Anyone taking this can take inspiration from the great job from this: https://github.com/julianocosta89/opentelemetry-microservices-demo/pull/1/files

[mathieu-benoit]

The OT community bumped it to Java 18: https://github.com/open-telemetry/opentelemetry-demo/tree/main/src/adservice

BOA moved to Java 17: https://github.com/GoogleCloudPlatform/bank-of-anthos/pull/712

Just sharing.

[mathieu-benoit]

Fixed by https://github.com/GoogleCloudPlatform/microservices-demo/pull/1007, with openjdk:18 actually.