Fix crash when setting the masking of the new feed items button if the context is null

As the fragment context can be null in some cases, we have to make sure that
the context is not null before calling
DeviceUtils.hasAnimationsAnimatorDurationEnabled.

If the context is null, the button will now not be hidden automatically.

Author: AudricV

app/src/main/java/org/schabi/newpipe/local/feed/FeedFragment.kt

@@ -607,9 +607,13 @@ class FeedFragment : BaseStateFragment<FeedState>() {
                 execOnEnd = {
                     // Disabled animations would result in immediately hiding the button
                     // after it showed up
-                    if (DeviceUtils.hasAnimationsAnimatorDurationEnabled(context)) {
-                        // Hide the new items-"popup" after 10s
-                        hideNewItemsLoaded(true, 10000)
+                    // Context can be null in some cases, so we have to make sure it is not null in
+                    // order to avoid a NullPointerException
+                    context?.let {
+                        if (DeviceUtils.hasAnimationsAnimatorDurationEnabled(it)) {
+                            // Hide the new items button after 10s
+                            hideNewItemsLoaded(true, 10000)
+                        }
                     }
                 }
             )