Upgrade Prettier from 1.17 to 2.0.2.

Summary:
This gets us on the latest Prettier 2.x:
https://prettier.io/blog/2020/03/21/2.0.0.html

Notably, this adds support for TypeScript 3.8,
which introduces new syntax, such as `import type`.

Reviewed By: zertosh

Differential Revision: D20636268

fbshipit-source-id: fca5833d003804333a05ba16325bbbe0e06d6c8a

Libraries/Components/DrawerAndroid/DrawerLayoutAndroid.android.js

@@ -237,7 +237,7 @@ class DrawerLayoutAndroid extends React.Component<Props, State> {
     );
   }
 
-  _onDrawerSlide = event => {
+  _onDrawerSlide = (event) => {
     if (this.props.onDrawerSlide) {
       this.props.onDrawerSlide(event);
     }
@@ -258,7 +258,7 @@ class DrawerLayoutAndroid extends React.Component<Props, State> {
     }
   };
 
-  _onDrawerStateChanged = event => {
+  _onDrawerStateChanged = (event) => {
     if (this.props.onDrawerStateChanged) {
       this.props.onDrawerStateChanged(
         DRAWER_STATES[event.nativeEvent.drawerState],