Upgrade to RN v0.64!

.flowconfig

@@ -59,6 +59,19 @@ flow-typed/expo-screen-orientation_vx.x.x.js
 ; counterparts in node_modules/react-native:
 flow-typed/jest_v26.x.x.js
 
+[declarations]
+; We should be able to remove this once we're on RN v0.65, which has
+; facebook/react-native@bac2c2c80. RN v0.64.2 was released without adding
+; error codes to several `$FlowFixMe`s, so we'd otherwise get 12 warnings in
+; this file, like
+;
+;   Suppression is missing a code. Please update this suppression to use an
+;     error code: $FlowFixMe[invalid-export]
+;
+; We still want the module's types to be used, so `declarations` seemed like
+; the best place to handle something like this:
+;   https://flow.org/en/docs/config/declarations/
+.*/node_modules/react-native/index.js
 
 [strict]
 ; These apply only to files where `@flow strict` is enabled.
@@ -113,8 +126,12 @@ module.file_ext=.js
 module.file_ext=.json
 module.file_ext=.ios.js
 
-; We can remove this on Flow v0.134 or later, when it's on by default.
-types_first=true
+; This is the future of Flow; see
+;   https://medium.com/flow-type/how-to-upgrade-to-exact-by-default-object-type-syntax-7aa44b4d08ab.
+; But we should anticipate that not all our third-party code acts sensibly
+; when this is turned on (e.g., see dfa52ab46). As of turning it on, though,
+; we're error-free!
+exact_by_default=true
 
 [version]
-^0.128.0
+^0.137.0

android/build.gradle

@@ -28,7 +28,7 @@ buildscript {
     }
     dependencies {
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
-        classpath 'com.android.tools.build:gradle:3.5.4'
+        classpath 'com.android.tools.build:gradle:4.1.0'
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files

flow-typed/@react-navigation/bottom-tabs_v5.x.x.js

@@ -68,7 +68,7 @@ declare module '@react-navigation/bottom-tabs' {
   }
 
   // Vaguely copied from
-  // react-native/Libraries/Animated/src/nodes/AnimatedValue.js
+  // react-native/Libraries/Animated/nodes/AnimatedValue.js
   declare type ValueListenerCallback = (state: { value: number, ... }) => void;
   declare interface AnimatedValue {
     constructor(value: number): void;

flow-typed/@react-navigation/drawer_v5.x.x.js

@@ -68,7 +68,7 @@ declare module '@react-navigation/drawer' {
   }
 
   // Vaguely copied from
-  // react-native/Libraries/Animated/src/nodes/AnimatedValue.js
+  // react-native/Libraries/Animated/nodes/AnimatedValue.js
   declare type ValueListenerCallback = (state: { value: number, ... }) => void;
   declare interface AnimatedValue {
     constructor(value: number): void;

flow-typed/@react-navigation/material-top-tabs_v5.x.x.js

@@ -68,7 +68,7 @@ declare module '@react-navigation/material-top-tabs' {
   }
 
   // Vaguely copied from
-  // react-native/Libraries/Animated/src/nodes/AnimatedValue.js
+  // react-native/Libraries/Animated/nodes/AnimatedValue.js
   declare type ValueListenerCallback = (state: { value: number, ... }) => void;
   declare interface AnimatedValue {
     constructor(value: number): void;

flow-typed/@react-navigation/native_v5.x.x.js

@@ -68,7 +68,7 @@ declare module '@react-navigation/native' {
   }
 
   // Vaguely copied from
-  // react-native/Libraries/Animated/src/nodes/AnimatedValue.js
+  // react-native/Libraries/Animated/nodes/AnimatedValue.js
   declare type ValueListenerCallback = (state: { value: number, ... }) => void;
   declare interface AnimatedValue {
     constructor(value: number): void;

flow-typed/@react-navigation/stack_v5.x.x.js

@@ -68,7 +68,7 @@ declare module '@react-navigation/stack' {
   }
 
   // Vaguely copied from
-  // react-native/Libraries/Animated/src/nodes/AnimatedValue.js
+  // react-native/Libraries/Animated/nodes/AnimatedValue.js
   declare type ValueListenerCallback = (state: { value: number, ... }) => void;
   declare interface AnimatedValue {
     constructor(value: number): void;

ios/Podfile

@@ -9,19 +9,20 @@ require_relative '../node_modules/react-native-unimodules/cocoapods.rb'
 target 'ZulipMobile' do
   config = use_native_modules!
 
-  use_react_native!(:path => config[:reactNativePath])
+  use_react_native!(
+    :path => config[:reactNativePath],
+    # to enable hermes on iOS, change `false` to `true` and then install pods
+    :hermes_enabled => false
+  )
 
   # Enables Flipper.
   #
   # Note that if you have use_frameworks! enabled, Flipper will not work and
-  # you should disable these next few lines.
-  use_flipper!(
-    'Flipper' => '0.75.1',
-    'Flipper-Folly' => '2.5.3',
-    'Flipper-RSocket' => '1.3.1',
-  )
+  # you should disable the next line.
+  use_flipper!()
+
   post_install do |installer|
-    flipper_post_install(installer)
+    react_native_post_install(installer)
   end
 
   # unimodules provides Expo packages individually.