Move the git commit parsing out of the start.sh and into the build

[jonespm]

Thank you for contributing to this project!

Describe your problem or feature you'd like added

Currently, git values are parsed in the start.sh script at runtime. This requires git be available at runtime. Because of occasional security issues with git and libcurl it would be beneficial to just remove these packages. I believe we could just do it in the build and then remove them after.

Describe the solution you'd like

Add something like this to the Dockerfile.

RUN bash -l -c 'GIT_REPO="$(git config --local remote.origin.url)"; \
                GIT_COMMIT="$(git rev-parse HEAD)"; \ 
                GIT_BRANCH="$(git name-rev "$GIT_COMMIT" --name-only)"; \
                echo export GIT_REPO=$GIT_REPO > /etc/git.version; \
                echo export GIT_COMMIT=$GIT_COMMIT >> /etc/git.version; \
                echo export GIT_BRANCH=$GIT_BRANCH >> /etc/git.version'

Remove git and read it in the start script.

Describe any possible alternatives you've considered

Some hacky solutions for pasing the .git have been considered like

GIT_COMMIT="$(cat .git/HEAD | cut -c 1-7)
GIT_BRANCH="$(grep $GIT_COMMIT .git/packed-refs | sort | tail -n 1 | cut -d/ -f2- | rev | cut -d/ -f1 | rev)

But I don't really like those a lot

Additional context

It looks like you have to use a file and can't set these directly since every RUN only knows about it's own context.
https://stackoverflow.com/questions/34911622/dockerfile-set-env-to-result-of-command

[jonespm]

Test Plan:

1. Verify the footer still shows the Git version when logging in
   For instance something likeGit version: 8ef3a65 (commit) 2022.02.01 (branch)
   In the container there will also be a file with new information in /etc/git.version
2. Verify that the security issue around libssl is no longer present. (Either with docker scan my-learning-analytics-web or on Docker Hub)

[pushyamig]

test Pass

1. The Footer is showing current Git Version. I tested this from From Canvas test and Local myla instanse
2. I did a docker scan my-learning-analytics-web Locally myla build, I did not see the severity on libssl,