incidentd: cleaning up settings.proto

This also fixes dumping of settings that use a prefix.

Since the proto isn't being used yet, I thought it would be nice to
clean it up so we start using it with a clean format.

Bug: 74611860
Test: flash device and check incident output.
Change-Id: Ib99ccab7929208cf8b4404715b0bd417852314c6
3 files changed