ScrollView: Fix flow type for StickyHeaderComponentType
ScrollView: Fix flow type for StickyHeaderComponentType

Summary: The instance type wasn't being set properly. Using AbstractComponent

Reviewed By: lunaleaps

Differential Revision: D17859988

fbshipit-source-id: 95e2098a7218afeaf3f6ee39ba2b69170ee2f54c

janicduplessis/react-native,exponent/react-native,janicduplessis/react-native,javache/react-native,myntra/react-native,myntra/react-native,hoangpham95/react-native,javache/react-native,exponentjs/react-native,pandiaraj44/react-native,javache/react-native,exponentjs/react-native,janicduplessis/react-native,exponentjs/react-native,facebook/react-native,hammerandchisel/react-native,myntra/react-native,janicduplessis/react-native,pandiaraj44/react-native,pandiaraj44/react-native,myntra/react-native,arthuralee/react-native,janicduplessis/react-native,hammerandchisel/react-native,exponent/react-native,javache/react-native,exponent/react-native,hammerandchisel/react-native,janicduplessis/react-native,pandiaraj44/react-native,exponent/react-native,hoangpham95/react-native,facebook/react-native,exponentjs/react-native,javache/react-native,hoangpham95/react-native,pandiaraj44/react-native,exponent/react-native,exponentjs/react-native,myntra/react-native,pandiaraj44/react-native,javache/react-native,exponent/react-native,janicduplessis/react-native,hammerandchisel/react-native,facebook/react-native,myntra/react-native,hoangpham95/react-native,hammerandchisel/react-native,facebook/react-native,hammerandchisel/react-native,exponentjs/react-native,facebook/react-native,arthuralee/react-native,myntra/react-native,hoangpham95/react-native,arthuralee/react-native,facebook/react-native,janicduplessis/react-native,hoangpham95/react-native,hoangpham95/react-native,pandiaraj44/react-native,facebook/react-native,hammerandchisel/react-native,facebook/react-native,arthuralee/react-native,exponentjs/react-native,javache/react-native,arthuralee/react-native,facebook/react-native,exponent/react-native,javache/react-native,myntra/react-native,hoangpham95/react-native,exponentjs/react-native,exponent/react-native,myntra/react-native,javache/react-native,pandiaraj44/react-native,hammerandchisel/react-native