Allow user to specify EAP-SIM under PEAP

Allow the user to select EAP-SIM methods as a second phase after
an outer PEAP authentication.  This hides the "identity" and
"password" fields if one of these methods is selected.

Bug: 34835771
Test: Manual: Connect to PEAP/EAP-SIM AP
Change-Id: I7e448fbebd352a4b0facbfafa74afaff6b704386