Support to query TYPE_WIFI usage with subscriberId

Previous the API ignores subscriberId when network type is WIFI.
Allow caller to call querySummaryXXXX with TYPE: WIFI
+ subscriberId: IMSI to get carrier merged wifi usage which matches the wifi
network with the given IMSI.

Bug: 176396812
Test: atest -c NetworkStatsServiceTest
Change-Id: Ia033521a24e2bb56182d74a41bb2b39710571782
Merged-In: Ia033521a24e2bb56182d74a41bb2b39710571782