Frameworks: slimrecents: allow closing recents in middle of the open animation

As reported by Tejus Kandachar steps to reproduce:

Press Recents button and very quicky tap on one of the apps in the recents list,
just as recents list is sliding in. If done fast, the app opens but recents screen does not close.
If done normally it slides away as expected.

Fix it with allowing to close the pannel as well on animation in state.

Change-Id: I4c52e6e6a4fd4b3a2a63bc364ead055f0e619faf