[WifiTrackerLib] Use open wifi package name for app label if applicable

App label of an open wifi network should use the open wifi package name
instead of the active scorer name.

Bug: 153352576
Test: manual visual verification that connected open wifi network uses
the open wifi package name instead of the active scorer name

Change-Id: I1e5dd068a5e9086143b928e3f16fec86b23b89b3
4 files changed