Sidecar container istio-proxy failed to start

Issue

• Sidecar container (istio-proxy) is not able to connect with istio pilot and hence config not received from Pilot.

# oc logs -c istio-proxy details-v1-7476c8db95-2dh8n --since=5m
2019-05-21T01:51:22.726549Z info    Envoy proxy is NOT ready: config not received from Pilot (is Pilot running?): cds updates: 0 successful, 0 rejected; lds updates: 0 successful, 0 rejected
[2019-05-21 01:51:23.312][13][warning][config] [bazel-out/k8-opt/bin/external/envoy/source/common/config/_virtual_includes/grpc_stream_lib/common/config/grpc_stream.h:102] gRPC config stream closed: 14, upstream connect error or disconnect/reset before headers
2019-05-21T01:51:24.731051Z info    Envoy proxy is NOT ready: config not received from Pilot (is Pilot running?): cds updates: 0 successful, 0 rejected; lds updates: 0 successful, 0 rejected
2019-05-21T01:51:26.726115Z info    Envoy proxy is NOT ready: config not received from Pilot (is Pilot running?): cds updates: 0 successful, 0 rejected; lds updates: 0 successful, 0 rejected
2019-05-21T01:51:28.726393Z info    Envoy proxy is NOT ready: config not received from Pilot (is Pilot running?): cds updates: 0 successful, 0 rejected; lds updates: 0 successful, 0 rejected

• proxy-config is not getting updated