They are introduced for the device owner process logging feature.
That is, for enterprise-owned devices with device owner app provisioned,
the device owner may choose to turn on additional device-wide logging for
auditing and intrusion detection purposes. Logging includes histories of
app process startup, commands issued over ADB and lockscreen unlocking
attempts. These logs will available to the device owner for analysis,
potentially shipped to a remote server if it chooses to.

ro.device_owner will be a master switch to turn off logging, if the device
has no device owner provisioned. persist.logd.security is a switch that
device owner can toggle (via DevicePoliyManager) to enable/disable logging.
Writing to both properties should be only allowed by the system server.

Bug: 22860162
Change-Id: Iabfe2347b094914813b9d6e0c808877c25ccd038