WifiConfigStore: Remove class

Remove the existing WifiConfigStore class. Move all the existing
functionality to two separate classes:
1. WifiSupplicantControl: For any wpa_supplicant operations.
2. WifiKeyStore: For any key management operations.

This CL doesn't change any functionality, it's only a refactor.

BUG: 29394274
BUG: 29396499
Change-Id: Ic3d3f9eb3c241f34f2fddcfa67374c9a98277e0a
TEST: Unit tests
TEST: Successfully associated the device with GoogleGuest.
7 files changed
tree: 37961b9449de03aaee2c66005890b04286036703
  1. libwifi_hal/
  2. libwifi_system/
  3. service/
  4. tests/