avoid NPE for voice recording slider

Exception java.lang.NullPointerException:
  at com.nextcloud.talk.controllers.ChatController$onViewBound$11.onTouch (ChatController.kt:858)
  at android.view.View.dispatchTouchEvent (View.java:15072)
  at android.view.ViewGroup.dispatchTransformedTouchEvent (ViewGroup.java:3923)
  at android.view.ViewGroup.dispatchTouchEvent (ViewGroup.java:3597)
  at android.view.ViewGroup.dispatchTransformedTouchEvent (ViewGroup.java:3923)
  at android.view.ViewGroup.dispatchTouchEvent (ViewGroup.java:3597)
  at android.view.ViewGroup.dispatchTransformedTouchEvent (ViewGroup.java:3923)
  at android.view.ViewGroup.dispatchTouchEvent (ViewGroup.java:3597)
  at android.view.ViewGroup.dispatchTransformedTouchEvent (ViewGroup.java:3923)
  at android.view.ViewGroup.dispatchTouchEvent (ViewGroup.java:3597)
  at android.view.ViewGroup.dispatchTransformedTouchEvent (ViewGroup.java:3923)
  at android.view.ViewGroup.dispatchTouchEvent (ViewGroup.java:3597)
  at android.view.ViewGroup.dispatchTransformedTouchEvent (ViewGroup.java:3923)
  at android.view.ViewGroup.dispatchTouchEvent (ViewGroup.java:3597)
  at android.view.ViewGroup.dispatchTransformedTouchEvent (ViewGroup.java:3923)
  at android.view.ViewGroup.dispatchTouchEvent (ViewGroup.java:3597)
  at android.view.ViewGroup.dispatchTransformedTouchEvent (ViewGroup.java:3923)
  at android.view.ViewGroup.dispatchTouchEvent (ViewGroup.java:3597)
  at android.view.ViewGroup.dispatchTransformedTouchEvent (ViewGroup.java:3923)
  at android.view.ViewGroup.dispatchTouchEvent (ViewGroup.java:3597)
  at android.view.ViewGroup.dispatchTransformedTouchEvent (ViewGroup.java:3923)
  at android.view.ViewGroup.dispatchTouchEvent (ViewGroup.java:3597)
  at android.view.ViewGroup.dispatchTransformedTouchEvent (ViewGroup.java:3923)
  at android.view.ViewGroup.dispatchTouchEvent (ViewGroup.java:3597)
  at com.android.internal.policy.DecorView.superDispatchTouchEvent (DecorView.java:1016)
  at com.android.internal.policy.PhoneWindow.superDispatchTouchEvent (PhoneWindow.java:1962)
  at android.app.Activity.dispatchTouchEvent (Activity.java:4265)
  at androidx.appcompat.view.WindowCallbackWrapper.dispatchTouchEvent (WindowCallbackWrapper.java:70)
  at com.android.internal.policy.DecorView.dispatchTouchEvent (DecorView.java:974)
  at android.view.View.dispatchPointerEvent (View.java:15335)
  at android.view.ViewRootImpl$ViewPostImeInputStage.processPointerEvent (ViewRootImpl.java:7820)
  at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess (ViewRootImpl.java:7593)
  at android.view.ViewRootImpl$InputStage.deliver (ViewRootImpl.java:6927)
  at android.view.ViewRootImpl$InputStage.onDeliverToNext (ViewRootImpl.java:6984)
  at android.view.ViewRootImpl$InputStage.forward (ViewRootImpl.java:6950)
  at android.view.ViewRootImpl$AsyncInputStage.forward (ViewRootImpl.java:7148)
  at android.view.ViewRootImpl$InputStage.apply (ViewRootImpl.java:6958)
  at android.view.ViewRootImpl$AsyncInputStage.apply (ViewRootImpl.java:7205)
  at android.view.ViewRootImpl$InputStage.deliver (ViewRootImpl.java:6931)
  at android.view.ViewRootImpl$InputStage.onDeliverToNext (ViewRootImpl.java:6984)
  at android.view.ViewRootImpl$InputStage.forward (ViewRootImpl.java:6950)
  at android.view.ViewRootImpl$InputStage.apply (ViewRootImpl.java:6958)
  at android.view.ViewRootImpl$InputStage.deliver (ViewRootImpl.java:6931)
  at android.view.ViewRootImpl.deliverInputEvent (ViewRootImpl.java:10422)
  at android.view.ViewRootImpl.doProcessInputEvents (ViewRootImpl.java:10270)
  at android.view.ViewRootImpl.enqueueInputEvent (ViewRootImpl.java:10226)
  at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent (ViewRootImpl.java:10554)
  at android.view.InputEventReceiver.dispatchInputEvent (InputEventReceiver.java:259)
  at android.os.MessageQueue.nativePollOnce
  at android.os.MessageQueue.next (MessageQueue.java:335)
  at android.os.Looper.loopOnce (Looper.java:186)
  at android.os.Looper.loop (Looper.java:313)
  at android.app.ActivityThread.main (ActivityThread.java:8751)
  at java.lang.reflect.Method.invoke
  at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run (RuntimeInit.java:571)
  at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:1135)

Signed-off-by: Marcel Hibbe <dev@mhibbe.de>

app/src/main/java/com/nextcloud/talk/controllers/ChatController.kt

@@ -846,8 +846,10 @@ class ChatController(args: Bundle) :
 
                         showRecordAudioUi(true)
 
-                        if (sliderInitX == 0.0F) {
-                            sliderInitX = binding?.messageInputView?.slideToCancelDescription?.x!!
+                        binding?.messageInputView?.slideToCancelDescription?.x?.let {
+                            if (sliderInitX == 0.0F) {
+                                sliderInitX = it
+                            }
                         }
 
                         val movedX: Float = event.x