Logging improvements for time zone updates

Logging improvements for time zone updates:
1) Add EventLog entries time zone update service interactions.
2) Add more information to dumpsys logs to improve debugging.

Unit tests run with:

make -j30 FrameworksServicesTests
adb install -r -g \
  "out/target/product/angler/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"

Bug: 31008728
Test: See above for unit testing.
Test: Internal xTS tests
Test: adb shell dumpsys timezone
Test: adb logcat -b events -v threadtime -v printable -v uid -d *:v
Change-Id: I9356f4694e60b49e4b06aadd632d1bad517b8a29