Default operator (controller) memory resources are too low

[bukovjanmic]

Operator (as distributed via OLM) has default memory limit set to 550MiB and memory request to 20MiB.

Our monitoring shows that the memory usage spikes a bit higher, on our relatively small cluster (4 worker nodes, tens of Grafana CRs) the memory usage oscilates between 540Mi and 683Mi, without any intervention the operator gets continuously OOMKilled.

On our largest cluster, the memory consumption oscilates around 2-2.1 GB of memory.

While we know how to adjust the values for individual operator instances, the defaults should probably be changed to something reasonable, I suggest 600MiB as memory.request and 2.5GiB for memory.limit.

The default for memory request (20 MiB) is way off, it seems, the operator has never such consumption.