Fix `Device.get_top_activity_name` regex match: updated latest implementation in droidbot

[Juicestus]

I was getting the following warning and the system was failing: WARNING:Device:Unable to get top activity name. The regex match of Device.get_top_activity_name needed to be updated.

This was fixed in a more recent version of droidbot (see permalink), so I pulled that change over to this version.