Update TabBarBottom to accept styling for animations (#2945)

* Update TabBarBottom.js

* Update TabNavigator-test.js.snap

* Update TabView-test.js.snap

packages/react-navigation/src/navigators/__tests__/__snapshots__/TabNavigator-test.js.snap

@@ -66,6 +66,7 @@ exports[`TabNavigator renders successfully 1`] = `
   </View>
   <View
     collapsable={undefined}
+    style={undefined}
   >
     <View
       onLayout={[Function]}

packages/react-navigation/src/views/TabView/TabBarBottom.js

@@ -41,6 +41,7 @@ type Props = {
   getTestIDProps: (scene: TabScene) => (scene: TabScene) => any,
   renderIcon: (scene: TabScene) => React.Node,
   style?: ViewStyleProp,
+  animateStyle?: ViewStyleProp,
   labelStyle?: TextStyleProp,
   tabStyle?: ViewStyleProp,
   showIcon?: boolean,
@@ -203,6 +204,7 @@ class TabBarBottom extends React.PureComponent<Props, State> {
       activeBackgroundColor,
       inactiveBackgroundColor,
       style,
+      animateStyle,
       tabStyle,
       isLandscape,
     } = this.props;
@@ -219,7 +221,7 @@ class TabBarBottom extends React.PureComponent<Props, State> {
     ];
 
     return this.state.isVisible ? (
-      <Animated.View>
+      <Animated.View style={animateStyle}>
         <SafeAreaView
           style={tabBarStyle}
           forceInset={{ bottom: 'always', top: 'never' }}

packages/react-navigation/src/views/__tests__/__snapshots__/TabView-test.js.snap

@@ -22,6 +22,7 @@ exports[`TabBarBottom renders successfully 1`] = `
 >
   <View
     collapsable={undefined}
+    style={undefined}
   >
     <View
       onLayout={[Function]}