1. If the runnable for performing a long press is not
removed when all pointers are up and it is executed
the explorer gets into delegating mode with no pointer
down and the next down crashes the explorer. Added
code to remove the long press runnable in a few places
it was missing and also added a safety in the runnable
to avoid executing it in case there are no active pointers.
bug:6557183
Change-Id: I9dab3de88fd08d8e2b38af18249ac551837c0736
ebac1b79c4