[MS19.1] Fix several hidden API dependencies

This includes:
1. Use android.util.IndentingPrintWriter instead of the
   deprecated internal one.
2. Replace usages of IntArray with CollectionUtils and ArrayList.
3. Replace usages of ArrayUtils with CollectionUtils.
4. Refactor MathUtils.constrain functions into NetworkStatsUtils.
5. Replace Maps.newHashMap and Lists.newArrayList with public
   class constructors.
6. Replace Slog with Log.

Test: FrameworksNetTests NetworkStaticLibTests
Bug: 204830222
Change-Id: If009194ad5668a6d48dd341ea6d325028ce56d42