title: React Native Animation font size input doesn't work
body: <p>Hello React Develelopers, my question:</p>
  <p>I want simply animate font size of placeholder by using clicking on it by using onFocus in my TextInput.</p>
  <p>Using expo and creating in state InputsMarginTop:0 is everything ok but using
  inputsFontSize: new Animated.Value(22) my expo is crashing.
  Why it doesn't work?</p>
  <pre><code>    import React, { Component } from 'react'
      import { StyleSheet, Text, View, ImageBackground, TextInput, Animated } from 'react-native'
          export default class AnimatedLoginScreen extends Component {
          state = {
              blur: 2,
              alfpha: 0.2,
              theme: 'dark',
              InputsMarginTop: new Animated.Value(11),
              inputsFontSize: new Animated.Value(22)
          }
  handleFocus = () =&gt; {
          Animated.timing(this.state.InputsMarginTop, {
              toValue: 55,
              duration: 1000
          }).start()
      }
  
      render() {
          const blackOrWhite = this.state.theme === &quot;dark&quot; ? &quot;white&quot; : &quot;white&quot;
          const { inputsFontSize } = this.state
  
  
          return (
  
  
              &lt;ImageBackground style={styles.bg} source={require('../assets/mountains.jpg')}&gt;
                  &lt;View style={[styles.container,
                  { backgroundColor: this.state.theme === 'dark' ? &quot;rgba(0,0,0,0.5)&quot; : &quot;rgba(255,255,255,0.3)&quot; }
                  ]}&gt;
  
  
                      &lt;View style={styles.headContainer}&gt;
                          &lt;Text style={styles.text}&gt;Sing In&lt;/Text&gt;
                          &lt;Text style={{ fontSize: 22, marginTop: 5 }}&gt;/UP&lt;/Text&gt;
                      &lt;/View&gt;
  
                      &lt;Animated.View style={[styles.inputContainer, { marginTop: this.state.InputsMarginTop }]}&gt;
                          &lt;TextInput
                              style={[styles.input, { fontSize: inputsFontSize, borderBottomWidth: 2, borderColor: blackOrWhite }]}
                              placeholder=&quot;Username&quot;
                              placeholderTextColor={blackOrWhite}
                              onFocus={() =&gt; { this.handleFocus() }}
                          /&gt;
                        
                      &lt;/Animated.View&gt;
  
  
                  &lt;/View&gt;
  
              &lt;/ImageBackground&gt;
  
  
          )
      }
  
  }
  </code></pre>
  <p>Thanks for your answers :)</p>