Add `pull down` icon and gesture

[Manish Ram]

Add pull down icon and gesture

Design:
https://www.figma.com/file/h6f3frXkqhEegiHdmQFhRR/Cryptocurrency-App?node-id=364%3A2127

[Severyn]

@manishram, @zinoadidi Fixed it.

[Manish Ram]

I was expecting smooth animation based on the position of a finger on the screen while making gestures.
Like this:

[Severyn]

@manishram Fixed.