Clean up ConversationCursor listeners

The activity controller listener needs to be cleaned up on orientation
change; onDestroy is a good place to do that (onLoaderReset isn't called
on orientation change).

Also ignore stale refresh-ready signals, since they may fire after a
controller is destroyed.

Bug: 7564651
Change-Id: I1b9b7e63cca3c4bf4120e7b5ce93daccb3f33ee7
1 file changed