WifiBackupRestore: Parse auth_alg from supplicant backup data

This is the legacy Pre-O backup format. Add parsing support for auth
algorithm field.

Bug: 151702376
Test: atest com.android.server.wifi
Change-Id: I271af411560808714222726c27bf1f8aa56bc30f
2 files changed
tree: 0022f09c9fb342797263282594e6ee96814c8b12
  1. apex/
  2. service/
  3. metrics_pdd_hook.py
  4. PREUPLOAD.cfg