Summary:
1. Provide forceRTL function for developer to test RTL layout in LTR language bundle in I18nUtil and expose it in I18nManager.
2. Rename `allowRTL` and `setAllowRTL` functions
Reviewed By: fkgozali
Differential Revision: D3663693
fbshipit-source-id: 3db13a44c069ae73d1728c211306422db5dd8122
Summary: Rename the forceRTL to allowRTL so that make it much clear to read. And change a typo.
Reviewed By: fkgozali
Differential Revision: D3489235
fbshipit-source-id: b9803dfbcda2f764b7e752c9810cfc7a0b9fe39b
Summary: Provide function that could read the language currently used in the app, so the isRTL is using the app current using language to set isRTL.
Reviewed By: fkgozali
Differential Revision: D3480654
fbshipit-source-id: dea3ef4769296f594f7f32da2961b4fec1b99a7a
Summary: Create isDeviceLanguageRTL function to connect the OS language with isRTL. Now even if a new app could support RTL language, without setting forceRTL at JS side it won't directly change into RTL layout.
Reviewed By: fkgozali
Differential Revision: D3473109
fbshipit-source-id: ac1410c910e980d44750bb88cad7615febb9e076
Summary: Create a module for React Native to get IsRTL information and set ForceRTL function.
Reviewed By: fkgozali
Differential Revision: D3446871
fbshipit-source-id: 736edf138a89d222818071370ac49dc54bda63b7
Mengjue Wang