Update helm chart to account for changes to loadgenerator

[Mwad22]

Now that this issue in opentelemetry-demo repo has been resolved, the helm chart needs to be changed. Specifically, my PR maps the changes in this merged PR to do the following:

1. account for new environment variables in loadgenerator
2. deploy load generator as a service (by adding servicePort field) so users can use kubectl port-forward [service] [port] and interact with the locust UI
3. Generates the specific command to expose Locust UI in NOTES.txt.

NOTE: this can only be merged after new images are built/deployed as current images built the loadgenerator with different environment variables and a --headless tag that disables the locust UI

Re: Testing
I have tested the full functionality following helm chart changes on k8s by generating the template (using helm template) and replacing the image with my own docker image of locust.

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: Mwad22 (08794ce, 92c599e)

[dmitryax]

@Mwad22 please sign the CLA

[Mwad22]

@Mwad22 please sign the CLA

Just signed!

[TylerHelmuth]

@Mwad22 do you know how long it'll be till the new images our available?

[Mwad22]

@Mwad22 do you know how long it'll be till the new images our available?

I believe once this PR lands. @austinlparker @puckpuck I believe this was mentioned in the otel-demo slack, but can one of you confirm? thanks!

[TylerHelmuth]

@Mwad22 still interested in this PR?

[Mwad22]

Yes, will update it tomorrow!

[TylerHelmuth]

@Mwad22 I think there are some other defects affecting the demo chart that are causing your build to fail. I'll review this again when those are fixed in #344

[TylerHelmuth]

@Mwad22 please bump the chart version

[Mwad22]

@Mwad22 please bump the chart version

Just bumped it!

[TylerHelmuth]

@Mwad22 have you tested this branch with the new official demo images (0.3.4)?

[Allex1]

lgtm

[Mwad22]

@Mwad22 have you tested this branch with the new official demo images (0.3.4)?

@TylerHelmuth I just tested it again, everything seems to work as expected- with the new Locust UI and everything else!