Remove scanResultCache from WifiConfiguration

This is in preparation to use ScanDetail - which is a superset
of ScanResult - in wifi stack. There are no external users of
scanResultCache; so it can be safely removed.

Also fixed a javadoc comment for getPlmn()

Change-Id: I7c49532664ffe2e3e5e134bfcd42615d5999d02f
2 files changed