Create logged in and logged out context A/A tests

[selanthiraiyan]

We made a recent change to the ExPlat implementation in this commit.

We have to create two A/A tests to check that there is no bias in both logged-in and logged-out contexts.

• A/A test for logged-in context
  • Code change - New logged-in context A/A test to measure bias. #8236
  • Abacus - 20923-explat-experiment
• A/A test for logged-out context
  • Code change - New logged-out context A/A test to measure bias. #8237
  • Abacus - 20924-explat-experiment

[selanthiraiyan]

Closing as we decided to reuse the existing experiment proposals.

[jaclync]

There's no way to reuse the experiment name, so reopened the issue for 2 new A/A tests.