Replace NetworkPolicyManagerInternal#isUidRestrictedOnMeteredNetworks()

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, create NPMS#isUidRestrictedOnMeteredNetworks() and
NPM#isUidRestrictedOnMeteredNetworks() to replace
NPMI#isUidRestrictedOnMeteredNetworks().

Also correct the permission check in isUidNetworkingBlocked()
that needs to check OBSERVE_NETWORK_POLICY only.

Bug: 170598012
Test: atest FrameworksNetTests
Test: atest FrameworksCoreTests:NetworkPolicyManagerTest
Test: atest FrameworksServicesTests:NetworkPolicyManagerServiceTest
Test: atest CtsNetTestCases
Test: atest CtsHostsideNetworkTests
Change-Id: I5801a3a2076f3eb199a0226c38c85014b26c64e7