Ramping up Private Aggregation origin trial traffic to 7%

[Kevin Lee]

Private Aggregation API origin trial will be available at 7% of Chrome Stable unified experiment traffic from Tuesday June 6th 2023. The API will be available in the unified origin trial (5%), Protected Audience isolated trial (1%), and Shared Storage isolated trial (1%).  The traffic allocation for Protected Audience will not change since Private Aggregation is being added to an existing isolated experiment. 

For a deeper dive into these changes, please see the Relevance and measurement unified origin trial article on the Chrome blog. If you have any questions on this change, please file an issue in the Protected Audience GitHub repository.