Set up .flowconfig to support Haste and path-based imports (facebook#…

…24318)

Summary:
See facebook#24316 for the motivation.

By adding the .android.js and .ios.js extensions to the respective .flowconfig files, Flow is able to find files that either:

- Are required using Haste
- Are required using standard paths and have a .js extension
- Are required using standard paths and have a .platform.js subextension

[General] [Changed] - Adjusted .flowconfig to support both Haste and standard path-based requires
Pull Request resolved: facebook#24318

Differential Revision: D14822356

Pulled By: cpojer

fbshipit-source-id: dde0c83692d6170f4a44cd3fb8ede162054157e9

.flowconfig

@@ -44,6 +44,10 @@ emoji=true
 esproposal.optional_chaining=enable
 esproposal.nullish_coalescing=enable
 
+module.file_ext=.js
+module.file_ext=.json
+module.file_ext=.ios.js
+
 module.system=haste
 module.system.haste.use_name_reducers=true
 # keep the following in sync with server/haste/hasteImpl.js

.flowconfig.android

@@ -44,6 +44,10 @@ emoji=true
 esproposal.optional_chaining=enable
 esproposal.nullish_coalescing=enable
 
+module.file_ext=.js
+module.file_ext=.json
+module.file_ext=.android.js
+
 module.system=haste
 module.system.haste.use_name_reducers=true
 # keep the following in sync with server/haste/hasteImpl.js