MOGA's Pivot app has yet to be updated for Android 5.0 compatibility, so unfortunately there currently isn't a way to use MOGA Pivot with Bard's Tale.
However, certain MOGA gamepads (not all) have a HID mode switch on them that let you use HID mode with games. This should let you use your gamepad with Bard's Tale until Pivot is updated for Android 5.0 compatibility. Sorry for the inconvenience!