wifi: Add getCurrentShutdownTimeoutMills in SoftApInfo

PS: Rename ShutDown -> Shutdown for SAP usage.

Bug: 172978743
Test: atest -c FrameworksWifiTests
Test: atest -c FrameworksWifiApiTests
Change-Id: Id0ce9abba62747c160f1922cbd491e203e21bfa9
8 files changed