[BUG] SOF docker image has proxy settings hardcoded for Intel network

[kv2019i]

Describe the bug
The current SOF docker images have a hardcoded proxy set to Intel servers:
https://thesofproject.github.io/latest/getting_started/build-guide/build-with-docker.html

While testing the instructions from public network, scripts/docker-run.sh builds will fail due to this.

** Mitigation **
Modify scripts/docker-run.sh with

+     --env http_proxy \
+     --env https_proxy \
     --env CMAKE_BUILD_TYPE \
```

[lgirdwood]

@fredoh9 this is now fixed right ? if so please close.

[marc-hb]

I think it is not fixed because we still have commit f6f3ab0 copy apt.conf from host and set host proxy to environment

We could probably keep the image proxy-free and move any proxy configuration to scripts/docker-run.sh, more specifically docker run --env

[fredoh9]

@lgirdwood this is not fixed. @marc-hb I agree, we need to keep proxy-free for the docker image and set proxy when needed. I will work on it.