Extend long press timeout to 15 seconds

If the long press timeout is made too much longer than 15 seconds (and I have no need to find out how much longer), then the screen can actually shut off in the middle of a long press (if you have the screen timeout set to 15 seconds). In fact, setting the long press timeout to 15 seconds feels like I'm pushing it, IMO.

This should fix barrykn/android-cm7-bkndh1#8 for CM7.2.