Fix BlobProvider not working in newarch (#56369)

Summary:
Pull Request resolved: #56369

Blob images in RNTester work

Changelog: [Android][Fixed] Blob content provider did not work in new arch

Reviewed By: alanleedev

Differential Revision: D99836114

fbshipit-source-id: e672a920c2327dfe18edaae5291dd8bb8642cdd1

Author: javache

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/modules/blob/BlobProvider.kt

@@ -53,9 +53,8 @@ public class BlobProvider : ContentProvider() {
     var blobModule: BlobModule? = null
     val context = context?.applicationContext
     if (context is ReactApplication) {
-      @Suppress("DEPRECATION") val host = (context as ReactApplication).reactNativeHost
       val reactContext =
-          host.reactInstanceManager.currentReactContext
+          context.reactHost?.currentReactContext
               ?: throw RuntimeException("No ReactContext associated with BlobProvider")
       blobModule = reactContext.getNativeModule(BlobModule::class.java)
     }