SF: Fix duplicate callbacks from mirrored layers

When cloning layers, we would also clone the layer's
callback handles which resulted in SF emitting duplicate
callbacks.

Test: presubmit
Test: launcher does not ANR when switching wallpapers with screen recording enabled
Bug: 205922358

Change-Id: Ic0435164f27d9bca7f80fc57d9021a9f544c936f
4 files changed