Missing doorhanger and "netChange" telemetry when disconnecting and reconnecting to the network after changing the "DNSOverHTTPS" policy from false to true

[mariaberlinger]

[Affected Platforms]:

• Windows 10x64
• Windows 7x64
• macOS 10.15
• Ubuntu 18.04x64

[Affected Versions]:

• Firefox Release 70.0.1
• Firefox Beta 71.0b12
• Firefox Nightly 72.0a1 (BuildID 20191127215655)

[Prerequisites]:

• Have an active Normandy testing recipe for DoH.
• You are enrolled in the Treatment branch.
• Add the policies.json in the firefox/distribution folder with the following content: { "policies": { "DNSOverHTTPS": { "Enabled": true, "ProviderURL": "https://mozilla.cloudflare-dns.com/dns-query", "Locked": true } } }

[Steps to reproduce]:

1. Open the browser with the profile from prerequisites.
2. Go to about:config and add doh-rollout.enabled to true.
3. Go to about:telemetry#events-tab.
4. Disconnect from network.
5. Go to firefox/distribution and change the "DNSOverHTTPS" policy from false to true.
6. Reconnect to network.
7. Wait ~1min and refresh the about:telemetry#events-tab page.

[Expected result]:

• Doorhanger is displayed and telemetry event with Value netChange is recevied.

[Actual result]:

• Doorhanger isn't displayed and no telemetry event with "netChange" is generated.

[Notes]:

• The issue is reproducible with the 1.2.0rc2 version of the add-on.
• Following the steps mentioned above but without network disabling and enabling, just changing the "DNSOverHTTPS" policy from false to true and restart Firefox, doorhanger is missing too.
• I have attached a screen recording of the issue:

[maxxcrawford]

This is incorrect – if any policy is in place, the user should not see a door hanger, or have any heuristics ran period. This includes no telemetry for netChange events too.

[maxxcrawford]

cc @nhi-nguyen