Minimize PVC sizes for CI Pipeline

The bigbang CI pipeline use a reduced footprint for memory and CPU. But, uses the default settings for Persistent Volumes. Allocations of Persistent Volume Claims (PVC) can take additional time and can tax resources (e.g. Minio has 16 PVCs allocated with a size of 8Gi each).

Using the values.yaml for Big Bang's pipeline, reduce the size of the persistent volume claims to 256Mi and redundancy down to the minimum viable.