Move configurable vars to lower precedence location

[kbcz1989]

Description

All the variables are originally set in vars/main.yml. This makes configuring/overriding these variables much harder, due to Ansible variable precedence.

Ansible docs states:

defaults/:
Set defaults in roles to avoid undefined-variable errors. If you share your roles, other users can rely on the reasonable defaults you added in the roles/x/defaults/main.yml file, or they can easily override those values in inventory or at the command line. See Roles for more info

vars/:
Set variables in roles to ensure a value is used in that role, and is not overridden by inventory variables. If you are not sharing your role with others, you can define app-specific behaviors like ports this way, in roles/x/vars/main.yml. If you are sharing roles with others, putting variables here makes them harder to override, although they still can by passing a parameter to the role or setting a variable with -e

We are installing the agent on many hosts across different clouds, cloud regions and on-prem infrastructure and we are using inventory group or host vars to define the required variables. Passing different var files or defining vars as role inputs breaks our flow and significantly increases the possibility of human errors. Please consider this change.

Type of Change

• Bug Fix
• New Feature
• Breaking Change
• Refactor
• Documentation
• Other (please describe)

Checklist

• I have read the contributing guidelines
• Existing issues have been referenced (where applicable)
• I have verified this change is not present in other open pull requests
• Functionality is documented
• All code style checks pass
• New code contribution is covered by automated tests
• All new and existing tests pass