Remove VPN info arrays from NetworkStats(Observer|Recorder)

This change removes the now-unused VPN arrays in the network stats
observer and recorder classes. These are always null values in every
call site.

Bug: 113122541
Bug: 120145746
Bug: 129264869
Bug: 134244752
Test: FrameworksNetTest passing
Test: Manual tests show data usage fixes maintained.
Merged-In: Ieb8645acc400fdaeb0df7092c5369b96f9f35af9
Change-Id: I66f263d7e12bce7668901306c0c2ecdda634abaf
(cherry picked from commit 833603caabb1a850a63a970fc285b4c8ed7401f8)
3 files changed
tree: ca8902b2ae9abccf8661f45e3f2d4d1f3ae4abb7
  1. core/
  2. services/
  3. wifi/