fix repeatedly called onLongPress (to fix the Camera app issues etc.)

though decided not to be fixed in gingerbread ever, this bug is serious
enough to deserve to be fixed no matter what google's people decision is
see http://groups.google.com/group/android-platform/browse_thread/thread/59c0accd2e4a49b5#

Change-Id: I661859c590cc6329a6658cca1d30baac5679ad72