Output FGS notification permission state to log.

This field is populated on creation of the ServiceRecord as well as whenever the ServiceRecord is asked to post or update a notification.

Confirmed manually via statsd_testdrive, by turning on and off app notification permissions and then using play store app installs to trigger foreground services.

Bug: 194833441
Bug: 214065327
Test: TreeHugger, statsd_testdrive
Change-Id: I9fcf9950dfb93114f96eb11eaa73b89c98ae5ed3