refactor(policy): rename context-policy.proto name

proto/context_policy.proto

...n/java/eu/teraflow/policy/context/ContextGatewayImpl.java

src/policy/src/main/proto/context-policy.proto

src/policy/src/main/proto/context_policy.proto

.../generated-sources/grpc/context_policy/ContextPolicy.java

...ted-sources/grpc/context_policy/ContextPolicyService.java

...sources/grpc/context_policy/ContextPolicyServiceBean.java

...urces/grpc/context_policy/ContextPolicyServiceClient.java

...sources/grpc/context_policy/ContextPolicyServiceGrpc.java

...s/grpc/context_policy/MutinyContextPolicyServiceGrpc.java

src/policy/target/kubernetes/kubernetes.yml