WifiConfigStore: Remove OEM's config store after read

The first read will trigger the necessary migrations from OEM's config
store. Remove the store files after the read.

Also, rewired the WifiConfigStoreMigrationHolder object via
StoreData.deserializeData().

Bug: 149418926
Test: Device boots up and connects to wifi networks.
Test: atest com.android.server.wifi
Change-Id: Idcd48c4f1da30ad772eebf3010824a4432ba3fd7
30 files changed
tree: 21d77776b4a97e13d157bae8228bb70461f5ff5c
  1. apex/
  2. service/
  3. PREUPLOAD.cfg