Add a flag to specify whether to read detail data or not.

- for the app data usage summary, it only needs the total usage and
don't need the foreground/background differentiation. Add a flag to
indicate whether such details need to be retrieved.
- removed the network type parameter from the cycle data loader. The
network type can be inferred from the network template. Since we still
need to pass the network template, we don't need to explicitly sets the
network type.
- also removed the network policy parameter, and get it inside the
loader itself.

Bug: 111751694
Test: make RunSettingsLibRoboTests
Change-Id: I794d92f18132d163f81a357810bc74311f30dfd2