CI: fix watchman install errors and update ios simulators to version 11.2
CI: fix watchman install errors and update ios simulators to version 11.2

Summary:
Fixes watchman install errors.

Check that iphone 5s is booted properly on circle. Check brew install watchman succeeds.

[CI] - Fix ios version on circleci and fixes brew install watchman error
Closes https://github.com/facebook/react-native/pull/19166

Differential Revision: D7899295

Pulled By: hramos

fbshipit-source-id: 2260a2675879cf97fb0b2f11139d9bb84ce7444e

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