fix(docker-entrypoint.sh): update shebang to use /bin/env bash for be…

…tter portability

envoy/docker-entrypoint.sh

@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/env bash
 
 # Substitute environment variables in envoy.tpl.yaml and output to envoy.yaml
 envsubst < /etc/envoy/envoy.tpl.yaml > /etc/envoy/envoy.yaml