Update opacity when `disabled` prop is changed
Update opacity when `disabled` prop is changed

Summary:
fixes #17105

If you render

```
    <TouchableOpacity
        disabled={true}
        style={{opacity: 0.5}}
    >
        ...
    </TouchableOpacity>
```

and then

```
    <TouchableOpacity
        disabled={false}
        style={{opacity: 1}}
    >
        ...
    </TouchableOpacity>
```

The content of `TouchableOpacity` will still have opacity = 0.5 because real
opacity is controlled by animated property which should be properly updated
when `disabled` prop changes.

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Usually when a button or other UI component is built with `TouchableOpacity` you may want to change it's opacity if state of component is changed (enabled/disabled). Opacity provided in props is overridden with internally-managed animated value. Add extra check when component is updated to trigger opacity animation upon change of `disabled` flag.

You can use code from https://github.com/facebook/react-native/issues/17105.

(If this PR adds or changes functionality, please take some time to update the docs at https://github.com/facebook/react-native-website, and link to your PR here.)

[GENERAL][BUGFIX][TouchableOpacity] - trigger animation on `opacity` upon change in `disabled` prop.
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  CATEGORY
[----------]        TYPE
[ CLI      ]   [-------------]      LOCATION
[ DOCS     ]   [ BREAKING    ]   [-------------]
[ GENERAL  ]   [ BUGFIX      ]   [-{Component}-]
[ INTERNAL ]   [ ENHANCEMENT ]   [ {File}      ]
[ IOS      ]   [ FEATURE     ]   [ {Directory} ]   |-----------|
[ ANDROID  ]   [ MINOR       ]   [ {Framework} ] - | {Message} |
[----------]   [-------------]   [-------------]   |-----------|

[CATEGORY] [TYPE] [LOCATION] - MESSAGE

 EXAMPLES:

 [IOS] [BREAKING] [FlatList] - Change a thing that breaks other things
 [ANDROID] [BUGFIX] [TextInput] - Did a thing to TextInput
 [CLI] [FEATURE] [local-cli/info/info.js] - CLI easier to do things with
 [DOCS] [BUGFIX] [GettingStarted.md] - Accidentally a thing/word
 [GENERAL] [ENHANCEMENT] [Yoga] - Added new yoga thing/position
 [INTERNAL] [FEATURE] [./scripts] - Added thing to script that nobody will see
-->
Closes https://github.com/facebook/react-native/pull/17106

Differential Revision: D7158549

Pulled By: hramos

fbshipit-source-id: 209cc433b829b129810e8a884964c8853ca3fe8f

arthuralee/react-native,myntra/react-native,arthuralee/react-native,myntra/react-native,hoangpham95/react-native,pandiaraj44/react-native,hoastoolshop/react-native,facebook/react-native,myntra/react-native,pandiaraj44/react-native,hammerandchisel/react-native,hoangpham95/react-native,exponentjs/react-native,hammerandchisel/react-native,janicduplessis/react-native,facebook/react-native,javache/react-native,exponentjs/react-native,hoastoolshop/react-native,facebook/react-native,exponent/react-native,facebook/react-native,exponent/react-native,hoastoolshop/react-native,janicduplessis/react-native,hammerandchisel/react-native,hammerandchisel/react-native,pandiaraj44/react-native,javache/react-native,janicduplessis/react-native,facebook/react-native,exponent/react-native,janicduplessis/react-native,exponentjs/react-native,exponent/react-native,hammerandchisel/react-native,janicduplessis/react-native,hammerandchisel/react-native,exponentjs/react-native,myntra/react-native,janicduplessis/react-native,javache/react-native,exponent/react-native,hoastoolshop/react-native,myntra/react-native,pandiaraj44/react-native,hoastoolshop/react-native,arthuralee/react-native,pandiaraj44/react-native,hoangpham95/react-native,exponentjs/react-native,pandiaraj44/react-native,hoangpham95/react-native,hoangpham95/react-native,facebook/react-native,myntra/react-native,pandiaraj44/react-native,hoangpham95/react-native,hoastoolshop/react-native,exponent/react-native,javache/react-native,hoangpham95/react-native,exponentjs/react-native,exponent/react-native,hammerandchisel/react-native,myntra/react-native,myntra/react-native,arthuralee/react-native,hoastoolshop/react-native,exponent/react-native,javache/react-native,hammerandchisel/react-native,javache/react-native,facebook/react-native,javache/react-native,javache/react-native,hoangpham95/react-native,janicduplessis/react-native,arthuralee/react-native,javache/react-native,myntra/react-native,facebook/react-native,exponentjs/react-native,janicduplessis/react-native,exponentjs/react-native,pandiaraj44/react-native,facebook/react-native,hoastoolshop/react-native