[video_player]: Bump robolectric from 4.4 to 4.8.1 in /packages/video_player/video_player/example/android/app (#6025)

diff --git a/packages/video_player/video_player/example/android/app/build.gradle b/packages/video_player/video_player/example/android/app/build.gradle
index 7b3c7db..18e77a5 100644
--- a/packages/video_player/video_player/example/android/app/build.gradle
+++ b/packages/video_player/video_player/example/android/app/build.gradle
@@ -59,7 +59,7 @@
 
 dependencies {
     testImplementation 'junit:junit:4.13'
-    testImplementation 'org.robolectric:robolectric:4.4'
+    testImplementation 'org.robolectric:robolectric:4.8.1'
     testImplementation 'org.mockito:mockito-core:3.5.13'
     androidTestImplementation 'androidx.test:runner:1.1.1'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.1'