Fabric: Fixed incorrect SchedulerToolbox initialization in RCTSurfacePresenter
Fabric: Fixed incorrect SchedulerToolbox initialization in RCTSurfacePresenter

Summary: We have to use a getter instead of an ivar to enable lazy initialization of ContextContainer.

Reviewed By: mdvacca

Differential Revision: D15731877

fbshipit-source-id: eb4d0e70c337026a91cb12a3eb26ed4d94f39f9f

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