Fix reliability triggering

Fix reliability triggering in the time zone update
feature. The reliability triggering is there to
resume an update check when things go wrong. For
example, if the device is turned off after a
time zone data app is updated but before the time
zone update process has finished pulling the data
out and installing it in /data. The reliability
trigger happens when the device is idle and will
complete the work.

The idle triggering currently doesn't work as it
was implemented incorrectly.

The code has been changed to use the
JobScheduler to trigger on idle and scheduling
has been made explicit.

Unit tests run with:

make -j30 FrameworksServicesTests
adb install -r -g \
  "out/target/product/marlin/data/app/FrameworksServicesTests/FrameworksServicesTests.apk"
adb shell am instrument -e package com.android.server.timezone -w \
  com.android.frameworks.servicestests \
  "com.android.frameworks.servicestests/android.support.test.runner.AndroidJUnitRunner"

Test: See above
Test: Manual testing: adb shell am idle-maintenance, adb logcat/adb shell dumpsys timezone
Test: PTS: run pts -m PtsTimeZoneTestCases
Bug: 65657543
Change-Id: Ibb2c537955d09a5d538c50490dae94a518522f19