Expose a method to take control of firmware path

Rather than exposing the firmware path directly, expose a helper method.
This method can be static, since we call it once from wificond's main()
and cannot effectively unittest changing filesystem permissions.

Hide the firmware path again after this change.

Bug: 31225859
Test: Can connect to networks on bullhead with this change.

Change-Id: I1b1640f552f78ede2adb7e1273d69cc606543c7b
3 files changed
tree: 4a08129e1b38a1747464261ccc9428cf20e0f14f
  1. libwifi_hal/
  2. libwifi_system/
  3. service/
  4. tests/