Replace NetworkPolicyManagerInternal#isUidNetworkingBlocked()

Connectivity service is going to become a mainline module which
will not able to access hidden APIs. NetworkPolicyManagerInternal
is a internal serivce that CS can't be access after be a mainline
module. Thus, replace NPMI#isUidNetworkingBlocked() to similar
method NPMS#isUidNetworkingBlocked() and create new API
NPM#isUidNetworkingBlocked() to support CS usage.

Bug: 170598012
Test: atest FrameworksNetTests
Test: atest FrameworksCoreTests:NetworkPolicyManagerTest
Test: atest FrameworksServicesTests:NetworkPolicyManagerServiceTest
Test: atest CtsNetTestCases
Test: atest CtsHostsideNetworkTests
Change-Id: Ic3427c71c395de787320f303c9513874b4d64f98