Notification statsd logs: Notification panel.

Experimenting with moving this logging to the SysUI side to be able to
log the complete panel, including any lifetime-extended items.

Test: atest NotificiationLoggerTest SystemUITests
Test: statsd_testdrive 245
Test: adb shell cmd stats print-logs && adb logcat -s statsd:I | grep ' (245)'

Bug: 146488473
Change-Id: I0a1a1ddd8838c002807e7137477175f0acceba98