Wifi: Add a flag to indicate duplicate network

Add a flag to indicate if a wifiConfiguration is duplicate or not
This flag decides whether the previous network history along
with IP and proxy configurations are required to be copied
or not.

Change-Id: I663d985031c82e64f889044441daee70d17e5ddc
CRs-Fixed: 760505
Revert "wlan: Provide runtime option to enable or disable rssi threshold (base)"

This reverts commit b95c030a6ffa22b8c96d5358ee34ed835085a172.

RSSI threshold parameters are now user configurable.Below are the
parameters.
THRESHOLD_UNBLACKLIST_HARD_5G
THRESHOLD_UNBLACKLIST_SOFT_5G
THRESHOLD_UNBLACKLIST_HARD_24G
THRESHOLD_UNBLACKLIST_SOFT_24G
THRESHOLD_INITIAL_AUTO_JOIN_ATTEMPT_RSSI_MIN_5G
THRESHOLD_INITIAL_AUTO_JOIN_ATTEMPT_RSSI_MIN_24G

Hence reverting the gerrit

Change-Id: I0d589cd494a488a4618434314e76fefde1275abd
CRs-Fixed: 757958