Do not report boot timings on first boot or runtime restart

During first boot after OTA, additional dexopting has to be done
during PM initialization. Timings for OTA are reported separately,
so we should ignore first boot to avoid skewing the metrics.

The following metrics were updated:
 - boot_system_server_init - check added for consistency with other
   metrics in SystemServer. The metric is actually unaffected by first boot,
   because dexopt will start later
 - boot_package_manager_init_ready
 - boot_system_server_init
 - framework_locked_boot_completed
 - framework_boot_completed

Test: manual + UserControllerTest pass
Bug: 32807863
Change-Id: Iff13697b7d4f9ff8439e1e932d7e276f48cd5c37