wlan: Do not disable the network on Assoc Reject/Authentication Failure.

A failed network, if disabled, would result in no further connection
attempts for the same.Thus, do not disable the network rather enable
all the disabled networks, as supplicant shall disable the networks
temporarily on subsequent failures and would give fair chance to
select the prioritized networks.

Change-Id: I27bfdfed420e935c1bc21fb968d6a5ba75ca92aa
CRs-fixed: 582883
Wifi: Enable Ad-Hoc (IBSS) network configuration

This adds two public but hidden variables to WifiConfiguration: isIBSS and
frequency. These are used for configuring IBSS mode.

WifiConfigStore is exended to get and set these variables to wpa_supplicant
(via WifiNative).

Change-Id: Iab02c3d738c05c2de036350ea77b78789213e357
Wifi: Add IBSS supported method

Add method isIbssSupported() to WifiManager and related classes to query wether
the driver supports IBSS mode. The query is answered by wpa_supplicants new
command "get_capability modes".

It will only return a correct result after WIFI_STATE_ENABLED has been
reached.

Change-Id: I93aa2fdff94cd897c91ec3beb7e58940d1de7b72