Summary:
While working on a feature in realized the buttons I built using `TouchableHighlight` were too dark when pressed.
When used white white views, `TouchableHighlight` produces the color `d4d5d5`. This is different from `dedede` which iOS uses.
Let's use opacity 0.85 instead of 0.8 to make the color match iOS. See a React Native view compared to iOS settings screen (same color for pressed items now): http://imgur.com/a/6CyL3
On Android, people should be using `TouchableNativeFeedback` everywhere.
Reviewed By: sahrens
Differential Revision: D3896168
fbshipit-source-id: a7dd12b4bde079b120faaffc36d25292533a2c6d