Replace hardcoded metered info by the real setting

Pass the actual metered information into
ADnsHelper_isUidNetworkingBlocked().

Extend an existing test so that it can verify the data saver feature on
a metered network.

Bug: 288340533
Test: atest resolv_integration_test
Change-Id: I5e9ac44d0ab78f4ec48f320fbf23393e63e3898b