role should not depend on ansible_user variable

Summary

role should not depend on ansible_user variable

Steps to reproduce

try to use install_base action without using ansible_user on host (using same user as local user)

Expected behavior

docker should install successfully and give user access to docker

Actual behavior

docker fail on adding access for user

Relevant logs and/or screenshots

TASK [docker : giving {{ ansible_user }} access to docker] ********************************************************************************************************
Friday 16 February 2018  09:26:33 +0100 (0:00:03.503)       0:03:23.212 *******
fatal: [baremetal]: FAILED! => {"msg": "The task includes an option with an undefined variable. The error was: 'ansible_user' is undefined\n\nThe error appears tohave been in '/all/Admin/TASK/projects/task-cloud/baremetal-manager/roles_external/docker/tasks/install_base_configuration.yml': line 29, column 3, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n\n- name: \"giving {{ ansible_user }} access to docker\"\n  ^ here\nWe could be wrong, but this one looks like it might be an issue with\nmissing quotes.  Always quote template expression brackets when they\nstart a value. For instance:\n\n    with_items:\n      - {{ foo }}\n\nShould be written as:\n\n    with_items:\n      - \"{{ foo }}\"\n\nexception type: <class 'ansible.errors.AnsibleUndefinedVariable'>\nexception: 'ansible_user' is undefined"}

Possible fixes

swap ansible_user to ansible_user_id which is populated in any case