RN: Revert Okio.buffer(…) Change from D72632266 (#50669)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/50669

Fixes a bug that was introduced while migrating from Java to Kotlin.

Changelog:
[Android][Changed] - Fixed a bug with synchronously fetching resources from Metro.

Reviewed By: cortinico, mdvacca

Differential Revision: D72878362

fbshipit-source-id: feb881fa51f6eaa2cb5c7ba87ac93b7fdc29dc2c

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/devsupport/DevServerHelper.kt

@@ -318,7 +318,9 @@ public class DevServerHelper(
         if (!response.isSuccessful || response.body() == null) {
           return null
         }
-        Okio.sink(outputFile).use { output -> response.body()?.source()?.buffer()?.readAll(output) }
+        Okio.sink(outputFile).use { output ->
+          Okio.buffer(response.body()?.source()!!).readAll(output)
+        }
         return outputFile
       }
     } catch (e: Exception) {