fix(example): Update the example to v1.2.0

[michaelbrewer]

Description of changes:

Also include some code clean up in general and try to get the gradle project to build

Checklist

• Meet tenets criteria
• Update tests
• Update docs
• PR title follows conventional commit semantics

[pankajagrawal16]

Thanks for the contribution @michaelbrewer

Even though this example project exists within the repo, we also have https://github.com/aws-samples/cookiecutter-aws-sam-powertools-java which we keep upto date with version updates and features.

But its good to have this example project upto date as well until we have it in the same repo.

[michaelbrewer]

@pankajagrawal16 thanks i will have a look at https://github.com/aws-samples/cookiecutter-aws-sam-powertools-java

I did run into alot of issues getting things to build or run in Intellij and the Gradle part does not work specifically. I will see if the cookiecutter has the same issues.