UPLOAD_RESULTS Variable for Dockerfile

[Kickball]

Currently the README lists an optional variable for the container image UPLOAD_RESULTS, which changes whether the results are publicly uploaded to OONI.

This doesn't currently exist in the Dockerfile.

Major complication is that the configuration for the OONI Probe is handled via a JSON file rather than CLI commands.

[Kickball]

This was originally implemented as a build-time argument in the Dockerfile which isn't a great solution as it would require multiple images/tags depending on the user's desire.

It has now been reimplemented to be configurable at run time. The implementation has been tested and shown working as below:

[username@hostname ooniprobe]$ docker run --rm -it --env OONIPROBE_UPLOAD_RESULTS='false' --env OONIPROBE_DEBUG='true' localhost/ooniprobe:latest
OONIPROBE_DEBUG environment variable is set to true
OONIPROBE_UPLOAD_RESULTS environment variable is set to: false
   • ooni version 3.16.3      
ooniprobe@d1c2e418707b:/$ ooniprobe run im
   • Running im tests
[engine] iplookup: using cloudflare
...
[engine] sessionresolver: http3://dns.google/dns-query... ok
[engine] session: using probe services: {Address:https://api.ooni.io Type:https Front:}
   3.57% facebook_messenger: measure dnslookup://stun.fbsbx.com: ok 
   7.14% facebook_messenger: measure tcpconnect://b-api.facebook.com:443: ok 
...
   100.00% signal: measure https://cdn2.signal.org/: ok 
[engine] sessionresolver: [{"URL":"http3://dns.google/dns-query","Score":0.9970166206448616},{"URL":"https://dns.google/dns-query","Score":0.692709609640232},{"URL":"https://dns.quad9.net/dns-query","Score":0.6907909087450356},{"URL":"https://cloudflare-dns.com/dns-query","Score":0.35360159054144014},{"URL":"https://mozilla.cloudflare-dns.com/dns-query","Score":0.029370097297182367},{"URL":"http3://mozilla.cloudflare-dns.com/dns-query","Score":0.011885990730552494},{"URL":"http3://cloudflare-dns.com/dns-query","Score":0.002391731970595146},{"URL":"system:///","Score":0}]
ooniprobe@d1c2e418707b:/$ ooniprobe list 1
┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
│ #1                                               │
│ facebook_messenger       ok: ✓                   │
│ success: ✓               uploaded: ❌             │
│ {"facebook_dns_blocking": false,                 │
│  "facebook_tcp_blocking": false}                 │
┢━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┪
│ #2                                               │
│ telegram                 ok: ✓                   │
│ success: ✓               uploaded: ❌             │
│ {"telegram_http_blocking": false,                │
│  "telegram_tcp_blocking": false,                 │
│  "telegram_web_blocking": false}                 │
...

Note the ❌ in the uploaded column of the results, which shows that the results were not uploaded.

The changes will shortly be pushed to GitHub.