Added a new "incidentReportApprover" permission protection flag.

This gives the ONE app installed on the system the permission to
authorize the sharing of incident and bug reports with an app.

Currently that app is PermissionController.  Package Manager
enforces that there is only one installed, and refused to boot
if that isn't the case.

Bug: 123543706
Test: bit GooglePermissionControllerTest:*
Change-Id: I76a7fad0ea36359bbb0ff09669df46202d059dab