In MBO 5.2.6 Test, the sigma dut will disable roaming by supplicant
and invoke roaming by "WMI_ROAM_INVOKE_CMDID" to FT roam to new AP.
Revert the previous change Ia471998cf631948d8ffa701e67fcee22eebb0fa0
to not set roaming mode to WMI_ROAM_SCAN_MODE_NONE for supplicant
disabled roaming because Firmware will not support force roaming by
"WMI_ROAM_INVOKE_CMDID" command in roam mode WMI_ROAM_SCAN_MODE_NONE.
The original issue of above change will be fixed in
If50a306b6019320ddab2ac1695a57718d27f477a.
Change-Id: I30e6405895bfa236a71f8f8d8fe3b7b933f40412
CRs-Fixed: 2755801
e5d49f68a6