Make java-test-image usable for testing in k8s (#10102)
Make java-test-image usable for testing in k8s (#10102)

### Motivation

When developing and testing Pulsar, it is very slow to build the pulsar-all image. 
The java-test-image can be built in less than 1.5 minutes on most laptops.
When attempting to use the apachepulsar/java-test-image:latest with a local k8s setup (microk8s), it was found out that startup fails since the Pulsar helm charts expect that `nc` and `nslookup` are installed.

### Modifications

Make `nc` and `nslookup` available to the java-test-image by adding netcat, dnsutils and iputils-ping to the packages to be installed. These packages are installed to the pulsar image and were missing from the java-test-image.
This change makes java-test-image usable for k8s installations (for developing and testing Pulsar itself).
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