Fix type of exported Touchables: ComponentType -> AbstractComponent (#28737)

Summary:
Fixes https://github.com/facebook/react-native/issues/28726

When importing TouchableOpacity, it is treated as any by Flow. Replacing ComponentType with AbstractComponent works.

The [Flow documentation](https://flow.org/en/docs/react/types/#toc-react-componenttype) says the following about ComponentType:
> Note: In 0.89.0+, React.ComponentType is an alias for React.AbstractComponent<Config, any>, which represents a component with config type Config and any instance type.

So I'm thinking that since the instance type is treated as any with ComponentType, Flow treats TouchableOpacity as any as well.

## Changelog

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[General] [Fixed] - Fix Touchable{Opacity,Bounce,Highlight} being exported as `any` (Flow)
Pull Request resolved: https://github.com/facebook/react-native/pull/28737

Test Plan: I have done the same changes to react-native in my project's node_modules and seen that the components TouchableOpacity went from any to AbstractComponent with some props. Now I have a bunch of errors because I'm sending in wrong props to some touchables, which is good!

Reviewed By: cpojer

Differential Revision: D21362601

Pulled By: TheSavior

fbshipit-source-id: 5b98cc79eaef034eccdb7f47242f9f44be2ef2b8

Libraries/Components/Touchable/TouchableBounce.js

@@ -214,4 +214,4 @@ class TouchableBounce extends React.Component<Props, State> {
 
 module.exports = (React.forwardRef((props, hostRef) => (
   <TouchableBounce {...props} hostRef={hostRef} />
-)): React.ComponentType<$ReadOnly<$Diff<Props, {|hostRef: mixed|}>>>);
+)): React.AbstractComponent<$ReadOnly<$Diff<Props, {|hostRef: mixed|}>>>);

Libraries/Components/Touchable/TouchableHighlight.js

@@ -380,4 +380,4 @@ class TouchableHighlight extends React.Component<Props, State> {
 
 module.exports = (React.forwardRef((props, hostRef) => (
   <TouchableHighlight {...props} hostRef={hostRef} />
-)): React.ComponentType<$ReadOnly<$Diff<Props, {|hostRef: mixed|}>>>);
+)): React.AbstractComponent<$ReadOnly<$Diff<Props, {|hostRef: mixed|}>>>);

Libraries/Components/Touchable/TouchableOpacity.js

@@ -299,4 +299,4 @@ class TouchableOpacity extends React.Component<Props, State> {
 
 module.exports = (React.forwardRef((props, hostRef) => (
   <TouchableOpacity {...props} hostRef={hostRef} />
-)): React.ComponentType<$ReadOnly<$Diff<Props, {|hostRef: mixed|}>>>);
+)): React.AbstractComponent<$ReadOnly<$Diff<Props, {|hostRef: mixed|}>>>);