[target allocator] Not run the target allocator as root

[iblancasa]

Currently, the target allocator is run as root. This prevents the target allocator from being run in OpenShift without special capabilities.

When the target allocator pod is created, the following error can be seen in the kubectl describe <pod name> command output:

  Warning  Failed          12s (x2 over 12s)  kubelet            Error: container create failed: time="2023-01-03T15:56:58Z" level=error msg="runc create failed: unable to start container process: exec: \"./main\": stat ./main: permission denied"

How to reproduce

1. Create an OCP cluster (version 4.11 in my case)
2. Build and push to a registry the OTEL Collector Operator and Target Allocator container images
3. $ kubectl create namespace oteltest
4. $ kubectl -n oteltest create rolebinding default-view-oteltest --role=pod-view --serviceaccount=oteltest:ta
5. $ kubectl create -f tests/e2e/targetallocator-features/00-install.yaml -n oteltest:ta
6. Wait until the pod creation fails ($ kubectl get pods -n oteltest)

Note
The step 4 is executed manually because, when applying the manifest, it will fail because the TestStep kind is part of KUTTL.