Sideways sliding using incorrect sliding distance

[joelandrews4]

When using either an START or END gravity, the user must ensure that the layout height is greater than (or equal to) the layout width for this library to work. My suspicion is that the layout_height attribute is used as the sliding distance even when a sideways orientation is specified.

Without delving into the code in this library, this assumption is backed up by looking at the sliding velocity with a layout with a small width and tall height when it is hidden - it leaves the screen very rapidly without the correct interpolation.