bluetooth: rename adapter, dont enable on boot, adjust cfg

[kajusnau]

Description of Changes

• Set default bluetooth adapter name to "Ghaf"
  • When the adapter is enabled and discoverable, other devices will be able to identify our system as "Ghaf" instead of "BlueZ [BlueZ version]"
  • Normally, BlueZ queries hostnamed for the hostname and uses that for the adapter name, but we don't have hostnamed enabled in most VMs, therefore we statically define the adapter name here.
• Adjusted default BlueZ config:
  • Enabled FastConnectable
  • Enabled JustWorksRepairing
  • Set Privacy to device
  • Reduced the DiscoverableTimeout from 180 to 60s

Type of Change

• New Feature
• Bug Fix
• Improvement / Refactor

Related Issues / Tickets

Checklist

• Clear summary in PR description
• Detailed and meaningful commit message(s)
• Commits are logically organized and squashed if appropriate
• Contribution guidelines followed
• Ghaf documentation updated with the commit - https://tiiuae.github.io/ghaf/
• Author has run make-checks and it passes
• All automatic GitHub Action checks pass - see actions
• Author has added reviewers and removed PR draft status

Testing Instructions

Applicable Targets

• Orin AGX aarch64
• Orin NX aarch64
• Lenovo X1 x86_64
• Dell Latitude x86_64
• System 76 x86_64

Installation Method

• Requires full re-installation
• Can be updated with nixos-rebuild ... switch
• Other:

Test Steps To Verify:

1. Verify no regression in general bluetooth functionality:
   • Devices can still connect
   • Bluetooth audio works
2. Verify Ghaf's bluetooth adapter can be identified as "Ghaf":
   • Open Bluetooth settings -> Bluetooth Adapters
   • Verify the adapter name is set to "Ghaf"

[milva-unikie]

Tested on Lenovo-X1 (nixos-rebuild switch) and Darter Pro (new image)

• Bluetooth speaker and microphone both work
• Bluetooth adapter is shown as Ghaf
• Bluetooth is disabled after boot