Support tabKey and key for tab keys
Support tabKey and key for tab keys

Summary:
Support tabKey and key properties for tab keys in Tabs/Tab.

tabKey > tab > key > tab_{idx}

Reviewed By: aigoncharov

Differential Revision: D37412130

fbshipit-source-id: 56ade27a02a7ba2926534a81d92dd1e9229576f4

facebook/flipper,facebook/flipper,facebook/flipper,facebook/flipper,facebook/flipper,facebook/flipper,facebook/flipper,facebook/flipper,facebook/flipper,facebook/flipper,facebook/flipper