[istio-opa] Mount different policies for different pods's sidecars

I followed [1] to add OPA sidecar to pods. However according to this, the policy which is configured in opa-policy config map will be distributed / mounted to all OPA sidecars. Is there any other way to distribute these policies ? I may need to mount pod specific policies.

What is the policy distribution mechanism with istio’s OPA sidecar ?

[1] https://github.com/open-policy-agent/opa-istio-plugin

@liminwang please help take a look

Add @tsandall to answer the question.