profcollect: Reduce background processing job priority

The processing job is non-critical but quite CPU intensive. Reducing
priority allows the system to throttle the job more aggresively.

Test: presubmit
Bug: 241948742
Change-Id: Ie7aa921dec1aa1f4f8582041dae1679950f4d868
(cherry picked from commit a26982f82123956b0fbec596e5d6a190087a0924)
Merged-In: Ie7aa921dec1aa1f4f8582041dae1679950f4d868
1 file changed