P3A traffic isn't sent to the p3a-json.brave.com endpoint

[GeetaSarvadnya]

Description

Found while testing #23147

P3A traffic isn't sent to the p3a-json.brave.com endpoint, This is a regression issue after removing p3a.brave.com via #23147

Steps to Reproduce

1. Clean profile 1.41.82
2. Open network Charles network monitoring tool
3. Launch brave beta 1.41.81
4. Waited for almost 1 hour, traffic is not sent to p3a-json.brave.com endpoint, I could see only one metric data listed

Actual result:

P3A traffic isn't sent to the p3a-json.brave.com endpoint

Expected result:

All the metrics from brave://local-state should be shown in the p3a-json.brave.com endpoint

Reproduces how often:

100%

Brave version (brave://version info)

Brave	1.41.82 Chromium: 103.0.5060.66 (Official Build) beta (64-bit)
Revision	20b1569438a85e631d15e83eb355e3e326e5da6f-refs/branch-heads/5060@{#1066}
OS	Windows 10 Version 21H2 (Build 19044.1766)

Version/Channel Information:

• Can you reproduce this issue with the current release? No
• Can you reproduce this issue with the beta channel? Yes
• Can you reproduce this issue with the nightly channel? Yes

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields? NA
• Does the issue resolve itself when disabling Brave Rewards? NA
• Is the issue reproducible on the latest version of Chrome? NA

Miscellaneous Information:

cc: @brave/qa-team @rillian @porteron @mattmcalister @rebron

The issue is reproduced by @rillian and @stephendonner, thanks both!

[GeetaSarvadnya]

@rillian Looks like P2A metrics are also affected by this issue. #22079 (comment).

@brave/legacy_qa Please verify the P2A metrics as well once the PR is up (follow the test plan from brave/brave-core#13538)

[kjozwiak]

Closing as brave/brave-core#14015 was merged into 1.41.x. The above will require 1.41.93 or higher for 1.41.x verification 👍

[GeetaSarvadnya]

Verification PASSED on

Brave | 1.41.93 Chromium: 103.0.5060.114 (Official Build) (64-bit)
-- | --
Revision | a1c2360c5b02a6d4d6ab33796ad8a268a6128226-refs/branch-heads/5060@{#1124}
OS | Windows 10 Version 21H2 (Build 19044.1766)

Basically we ensured P3A and P2A works as it works in 1.40.x due to brave/brave-core#14015

• Confirmed that P3A traffic is sent to the endpoint p3a-json.brave.com in 1.41.x
• Confirmed that all the P3A metrics are sent to the json format to p3a-json.brave.com in 1.41.x
• Confirmed that after reverting P3A protobuf submission Revert stopping P3A protobuf submission for 1.41 brave-core#14015, the traffic is sent to the old p3a.brave.com endpoint in the encoded format in 1.41.x
• Confirmed P2A metrics data sent correctly in both old p2a.brave.com and new json p2a.json.brave.com formats in 1.41.x
• Confirmed brave://local-state file has 6 records for p2a and the same is shown in both p2a-json.brave.com and p2a.brave.com endpoints
• Confirmed brave://local-state file has 47 records for p3a and the same is shown in both p3a-json.brave.com and p3a.brave.com endpoints

p3a data in brave://local-state	p3a.brave.com	p3a-json.brave.com

p2a data in brave://local-state	p2a.brave.com	p2a-json.brave.com