WifiBackupRestore: Logging changes

Changes in CL:
1. To reduce log spamming, dump out the raw backup data only in
bugreports if verbose logging is enabled.
2. Mask out the passwords from the backup data dump.
3. Move WifiBackupRestore module initialization to |WifiInjector| so
that |WifiStateMachine| can set the verbose loging level.
4. Cleanup some unused variables in |SupplicantNework| class.

BUG: 29051876
Change-Id: I6b58136057549ba1eb8a2845341be9fa072572b4
TEST: Manual tests
6 files changed
tree: 7c94976508bb53409e7916a70b5e3df54afed95c
  1. service/
  2. tests/