Write keepalive metrics periodically using alarms.

Use AlarmManger ELAPSED_REALTIME_WAKEUP to trigger writing the metrics
to statsd on an interval of 24 hours.

Bug: 273451360
Test: statsd_testdrive
Test: atest FrameworksNetTests
(cherry picked from https://android-review.googlesource.com/q/commit:19ea1502712ec988b52e5681816368106a6fd8cb)
Merged-In: I5e21de058336819189532beffe2b3239a3c69599
Change-Id: I5e21de058336819189532beffe2b3239a3c69599
3 files changed