Add an example using a user base image

## Expected Behavior

Base image must have a compatible libc, ssl.
The example should copy the istio-proxy and krun binaries:
- krun
- pilot-agent
- envoy
- envoy bootstrap template
- iptables-save
- (others to be identified )

We should include at least one example based on distroless and one on bionic or debian.
For 'proxyless gRPC' - we can also have an alpine one ( and no envoy ).