[SP12] Remove the usage of getVtDataUsage

Currently NetworkStatsService holding a lock when invoking
getVtDataUsage, which causes a lot of deadlock problems since
Phone will also have binder calls to system_server.

Thus, this change uses a new set of API to break such situation,
that allows VT to report stats asynchronously.

Test: atest FrameworksNetTests FrameworksTelephonyTests
Bug: 130855321
Fix: 143923500

Change-Id: Ifdb8599c3bade09208b4730710fc99da1afad71d