Switch to streaming data for time zone update

Switch to streaming data for time zone update rather than
loading it into memory first.

Also make sure that the ParcelFileDescriptor passed to the
service is closed in all cases.

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"

Test: See above
Test: Manual
Bug: 31008728
Change-Id: Ia1e27b204697caee62deb2a3d682800350bca800