NIFI-3314 Adjusting Dockerfile for Docker Hub to use defaults for ARGs

[apiri]

NIFI-3314 Adjusting Dockerfile for Docker Hub to use defaults for ARGs such that it does not need supporting build script. Making use of openjdk base image as the java image has been deprecated.

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[olegz]

Reviewing . . .

[olegz]

LGTM, merging