Get incidentd cts working again.

- The buffer size increased, and the CTS test that checked that
  was triggering.
- Privacy filtering wasn't working for the stack trace sections
- The incident command was not handling the default arguments correctly
- The throttler was throttling streaming reports, which made the
  test flaky.

Bug: 126253679
Test: atest CtsIncidentHostTestCases
Change-Id: I342cd7d0421ea8c22b7796fc99e779f21855af73