Poor range slider performance in Edit Element view

This issue has been migrated from mozilla/webmaker-android#1772.

It was originally written by flukeout on Sun May 10 2015 and had the following description:

I don't know exactly why or when this happens, but I'd say my success rate on the range sliders noticing I'm trying to slide them is about 50%.

On Mon May 11 2015, xmatthewx commented:

**@**flukeout - Nexus 4 or 5 with Android 5?

On Mon May 11 2015, flukeout commented:

**@**xmatthewx Nexus 4 with Android 5