Tests that withdrawing maintains the quota.

Initial storage
{
  "usage": 0,
  "quota": 1073741824,
  "overrideActive": false
}
Applying overrides from two sessions
{
  "usage": 0,
  "quota": 9000,
  "overrideActive": true
}
Disconnecting one session
{
  "usage": 0,
  "quota": 9000,
  "overrideActive": true
}