middleware: only show relevant input fields when configuring wifi
middleware: only show relevant input fields when configuring wifi

JIRA: EDISON-1470

initially both username and password fields were shown regardless
of the wifi security protocol in use. Changed this behavior to show
only relevant ones. For example, only password field is shown when
configuring a WPA personal network.

Change-Id: Ia40924ac183ab0e91267058ae616eb2cca816da4
Signed-off-by: Akshay Dua <a837d9a077e253c16abbd2d2b4cc517ed7de9fdf@intel.com>
Reviewed-on: http://git-ger-5.devtools.intel.com/gerrit/123646
Reviewed-by: Chenthati, PradeepX <ea0db43d929961e7db4a331f92abffaa996227a6@intel.com>
Reviewed-by: Maalem, Saadi <7c4e7ca09d3b1b268efd2bf38664e5587a4a4b82@intel.com>

01org/edison-oobe,pombreda/edison-oobe,01org/edison-oobe,srware/edison-oobe,srware/edison-oobe,srware/edison-oobe,pombreda/edison-oobe,srware/edison-oobe,01org/edison-oobe,pombreda/edison-oobe,01org/edison-oobe,pombreda/edison-oobe