Update test case Dockerfile

[cherylking]

Investigate whether the Dockerfile used in the test cases can be updated to run with a non-root user. They do a chown 1001 for some files, but do not switch to that user at the end of the file.

Affected files:

• https://github.com/OpenLiberty/liberty-tools-vscode/blob/main/src/test/resources/maven/liberty.maven.test.wrapper.app/Dockerfile
• https://github.com/OpenLiberty/liberty-tools-vscode/blob/main/src/test/resources/gradle/liberty.gradle.test.wrapper.app/Dockerfile

This was identified in the static app scan.