Test: remove bin_dir from other tasks move to common_vars.yml

Signed-off-by: ChengHao Yang <17496418+tico88612@users.noreply.github.com>

tests/common_vars.yml

@@ -4,6 +4,8 @@ deploy_netchecker: true
 dns_min_replicas: 1
 unsafe_show_logs: true
 
+bin_dir: "{{ '/opt/bin' if ansible_os_family == 'Flatcar' else '/usr/local/bin' }}"
+
 # Registry mirrors settings
 docker_registry_mirrors:
   - "https://mirror.gcr.io"