Initial codes for Quality network selection [DO NOT MERGE]

    In this change list, the old WifiAutojoin module is
    refactored initially. The old WifiAutojoinController is
    replaced with a new WifiQualifiedNetworkSelector.
    WifiConfiguration, WifiConfigureStore and
    WifiStateMachine have been modified accordingly. The new
    network selection logic is refactored with a more clear
    and deterministci one. To refer to thedescribed in
    details, in "Quality Network Selection and Connectivity
    Scan Management in N". The link of the document is:
    https://docs.google.com/document/d
    /1JPTa2NEk-PgjCJ16fIrR6ohV-kDKveDlYDOeiMCB2_c

Bug:26012244

Change-Id: I3df124c110e458e3b6bc29466b9046748d79582a