flow: Use path-based imports instead of Haste.

Part of the RN v0.60 -> v0.61 changes to the template app [1],
corresponding to facebook/react-native@bf8d91868 and a correction in
facebook/react-native@732ded7f7. This must happen at or after the
main upgrade commit because the former declares that it depends on
facebook/react-native#25100, which landed in
facebook/react-native@69d1ed731 and was released in v0.61.0.

[1]: https://react-native-community.github.io/upgrade-helper/?from=0.60.6&to=0.61.5

.flowconfig

@@ -2,14 +2,6 @@
 ; We fork some components by platform
 .*/*[.]android.js
 
-; Ignore unexpected extra "@providesModule"
-.*/node_modules/.*/node_modules/fbjs/.*
-
-; Ignore duplicate module providers
-; For RN Apps installed via npm, "Libraries" folder is inside
-; "node_modules/react-native" but in the source repo it is in the root
-node_modules/react-native/Libraries/react-native/React.js
-
 ; Ignore polyfills
 node_modules/react-native/Libraries/polyfills/.*
 
@@ -97,28 +89,11 @@ esproposal.nullish_coalescing=enable
 # The main warning is "Unused suppression comment".
 include_warnings=true
 
-
-module.system=haste
-module.system.haste.use_name_reducers=true
-# get basename
-module.system.haste.name_reducers='^.*/\([a-zA-Z0-9$_.-]+\.js\(\.flow\)?\)$' -> '\1'
-# strip .js or .js.flow suffix
-module.system.haste.name_reducers='^\(.*\)\.js\(\.flow\)?$' -> '\1'
-# strip .ios suffix
-module.system.haste.name_reducers='^\(.*\)\.ios$' -> '\1'
-module.system.haste.name_reducers='^\(.*\)\.android$' -> '\1'
-module.system.haste.name_reducers='^\(.*\)\.native$' -> '\1'
-module.system.haste.paths.blacklist=.*/__tests__/.*
-module.system.haste.paths.blacklist=.*/__mocks__/.*
-module.system.haste.paths.whitelist=<PROJECT_ROOT>/node_modules/react-native/Libraries/.*
-module.system.haste.paths.whitelist=<PROJECT_ROOT>/node_modules/react-native/RNTester/.*
-module.system.haste.paths.whitelist=<PROJECT_ROOT>/node_modules/react-native/IntegrationTests/.*
-module.system.haste.paths.blacklist=<PROJECT_ROOT>/node_modules/react-native/Libraries/react-native/react-native-implementation.js
-module.system.haste.paths.blacklist=<PROJECT_ROOT>/node_modules/react-native/Libraries/Animated/src/polyfills/.*
-
 munge_underscores=true
 
-module.name_mapper='^[./a-zA-Z0-9$_-]+\.\(bmp\|gif\|jpg\|jpeg\|png\|psd\|svg\|webp\|m4v\|mov\|mp4\|mpeg\|mpg\|webm\|aac\|aiff\|caf\|m4a\|mp3\|wav\|html\|pdf\)$' -> 'RelativeImageStub'
+module.name_mapper='^react-native$' -> '<PROJECT_ROOT>/node_modules/react-native/Libraries/react-native/react-native-implementation'
+module.name_mapper='^react-native/\(.*\)$' -> '<PROJECT_ROOT>/node_modules/react-native/\1'
+module.name_mapper='^[./a-zA-Z0-9$_-]+\.\(bmp\|gif\|jpg\|jpeg\|png\|psd\|svg\|webp\|m4v\|mov\|mp4\|mpeg\|mpg\|webm\|aac\|aiff\|caf\|m4a\|mp3\|wav\|html\|pdf\)$' -> '<PROJECT_ROOT>/node_modules/react-native/Libraries/Image/RelativeImageStub'
 
 suppress_type=$FlowIssue
 suppress_type=$FlowFixMe