BP-proc shares a volume with cmd/py-executor

During docker container creation, it seems the UID/GID for "onap" user are different values across bp-proc and py-exec.

blueprints processor uses omahoco1/alpine-java-python

From Dockerfile:

RUN addgroup -S onap && adduser -S onap -G onap 

command executor:  python:3.6-slim

From Dockerfile:

RUN groupadd -r onap && useradd -r -g onap onap 

py-executor:  python:3.7-slim

From Dockerfile:

 RUN groupadd -r onap && useradd -r -g onap onap

I think we should manually specify the UID/GID so that they will be consistent as there seems to be a difference across images.

# alpine
RUN addgroup -g 1000 docker && \
    adduser -u 1000 -G docker -h /home/docker -s /bin/sh -D docker
    
# debian / ubuntu
RUN addgroup --gid 1000 docker && \
    adduser --uid 1000 --ingroup docker --home /home/docker --shell /bin/sh --disabled-password --gecos "" docker
 

Previously, I also wonder if it was working as the /opt/app/onap was 777'ed