Replace UNSAFE_componentWillMount with componentDidMount
Replace UNSAFE_componentWillMount with componentDidMount

Summary:
Changelog:
[General] Replace UNSAFE_componentWillMount with componentDidMount in ScrollView

Reviewed By: nadiia

Differential Revision: D26375818

fbshipit-source-id: 1a33a7fddcf78c05cc1e4f04bd85b48a59290560

javache/react-native,myntra/react-native,arthuralee/react-native,myntra/react-native,myntra/react-native,janicduplessis/react-native,janicduplessis/react-native,janicduplessis/react-native,janicduplessis/react-native,facebook/react-native,facebook/react-native,pandiaraj44/react-native,janicduplessis/react-native,arthuralee/react-native,janicduplessis/react-native,myntra/react-native,janicduplessis/react-native,javache/react-native,javache/react-native,janicduplessis/react-native,facebook/react-native,myntra/react-native,pandiaraj44/react-native,pandiaraj44/react-native,myntra/react-native,pandiaraj44/react-native,pandiaraj44/react-native,facebook/react-native,pandiaraj44/react-native,javache/react-native,javache/react-native,myntra/react-native,javache/react-native,facebook/react-native,myntra/react-native,facebook/react-native,myntra/react-native,arthuralee/react-native,javache/react-native,facebook/react-native,javache/react-native,arthuralee/react-native,pandiaraj44/react-native,facebook/react-native,facebook/react-native,javache/react-native,pandiaraj44/react-native,arthuralee/react-native