Fix AppInfo drop target bug

Repro:
 - Pick up a shortcut from Workspace
 - Drop on AppInfo
 - Observe extra screen on right has not been removed

Change-Id: I6c68df27094d964308cc6e2a95917010784725a6
Merge branch 'cm-11.0' of https://github.com/CyanogenMod/android_packages_apps_Trebuchet into kk