Allow possibility to disable debugging for 3rd party apps support

Description

Some 3rd party apps are using the RootBeer lib to detect a ro.debuggable equal to 1 and consider that the device might be rooted, so won't run.

Allow the possibility to override the enable_target_debugging build variable with ENABLE_TARGET_DEBUGGING_OVERRIDE that will be used on stable builds.

Issue(s)

https://gitlab.e.foundation/e/backlog/-/issues/3646

Test procedures

1. Install the https://gitlab.e.foundation/e/priv/os/build/-/jobs/258419 build on a FP3
2. Install the Doctolib app.
3. Run Doctolib.
4. Doctolib shouldn't display a message saying that the device is rooted.
5. Doctolib should work properly.

Screenshots

With ro.debuggable=1

With ro.debuggable=0

Check list

• Self review
• Test procedure explained
• Tested on fresh install
• Tested applied as an update
• License
• Internal documentation
• User documentation