WifiBackupRestore: Add IpConfiguration to backup data

Add the IpConfiguration object associated with each WifiConfiguration
object to the backup data. Currently, this ip configuration information
is being backed up separately via IpConfigStore class in the
ipconfig.txt file.

While there,
1. Rename write/parse-WepKeys methods.
2. Prefix the existing write/parse-Configuration methods with |Wifi| to
differentiate from the new IpConfiguration methods.
3. Prefix the existing depth variables with |tag|.

BUG: 28967335
BUG: 29063894
Change-Id: Ie8ebb119e2b22e78e825aee2aa2f1bb992f0c149
TEST: Compiles & unit-test passes
2 files changed
tree: ebb1a10296ca5cf3c8dd8868c01cff08c7dd03ca
  1. service/
  2. tests/