Fixes more  @Nullable issues in System UI and WMShell.

Test: builds
Fix: 294098415
Change-Id: I64a2c95bbe889592806b01f288df32032b0cdc6a
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopTasksController.kt b/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopTasksController.kt
index d8ce427..1d46e75 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopTasksController.kt
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopTasksController.kt
@@ -275,7 +275,7 @@
      */
     fun onDesktopSplitSelectAnimComplete(taskInfo: RunningTaskInfo) {
         val wct = WindowContainerTransaction()
-        wct.setBounds(taskInfo.token, null)
+        wct.setBounds(taskInfo.token, Rect())
         shellTaskOrganizer.applyTransaction(wct)
     }
 
diff --git a/packages/SystemUI/src/com/android/keyguard/KeyguardSecurityViewTransition.kt b/packages/SystemUI/src/com/android/keyguard/KeyguardSecurityViewTransition.kt
index 96ac8ad..e1c060f 100644
--- a/packages/SystemUI/src/com/android/keyguard/KeyguardSecurityViewTransition.kt
+++ b/packages/SystemUI/src/com/android/keyguard/KeyguardSecurityViewTransition.kt
@@ -66,11 +66,11 @@
     }
 
     override fun createAnimator(
-        sceneRoot: ViewGroup?,
+        sceneRoot: ViewGroup,
         startValues: TransitionValues?,
         endValues: TransitionValues?
     ): Animator? {
-        if (sceneRoot == null || startValues == null || endValues == null) {
+        if (startValues == null || endValues == null) {
             return null
         }
 
diff --git a/packages/SystemUI/src/com/android/systemui/clipboardoverlay/ClipboardTransitionExecutor.kt b/packages/SystemUI/src/com/android/systemui/clipboardoverlay/ClipboardTransitionExecutor.kt
index 0b8e83e..1b45ecd 100644
--- a/packages/SystemUI/src/com/android/systemui/clipboardoverlay/ClipboardTransitionExecutor.kt
+++ b/packages/SystemUI/src/com/android/systemui/clipboardoverlay/ClipboardTransitionExecutor.kt
@@ -59,7 +59,7 @@
         context.startActivity(intent, transition.first.toBundle())
         val runner = RemoteAnimationAdapter(NULL_ACTIVITY_TRANSITION, 0, 0)
         try {
-            WindowManagerGlobal.getWindowManagerService()
+            checkNotNull(WindowManagerGlobal.getWindowManagerService())
                 .overridePendingAppTransitionRemote(runner, displayTracker.defaultDisplayId)
         } catch (e: Exception) {
             Log.e(TAG, "Error overriding clipboard app transition", e)
diff --git a/packages/SystemUI/src/com/android/systemui/screenshot/ActionIntentExecutor.kt b/packages/SystemUI/src/com/android/systemui/screenshot/ActionIntentExecutor.kt
index ecd4568..aa6bfc3 100644
--- a/packages/SystemUI/src/com/android/systemui/screenshot/ActionIntentExecutor.kt
+++ b/packages/SystemUI/src/com/android/systemui/screenshot/ActionIntentExecutor.kt
@@ -83,7 +83,7 @@
         if (overrideTransition) {
             val runner = RemoteAnimationAdapter(SCREENSHOT_REMOTE_RUNNER, 0, 0)
             try {
-                WindowManagerGlobal.getWindowManagerService()
+                checkNotNull(WindowManagerGlobal.getWindowManagerService())
                     .overridePendingAppTransitionRemote(runner, displayTracker.defaultDisplayId)
             } catch (e: Exception) {
                 Log.e(TAG, "Error overriding screenshot app transition", e)
diff --git a/packages/SystemUI/src/com/android/systemui/user/domain/interactor/GuestUserInteractor.kt b/packages/SystemUI/src/com/android/systemui/user/domain/interactor/GuestUserInteractor.kt
index f026f0f..bfed0c4 100644
--- a/packages/SystemUI/src/com/android/systemui/user/domain/interactor/GuestUserInteractor.kt
+++ b/packages/SystemUI/src/com/android/systemui/user/domain/interactor/GuestUserInteractor.kt
@@ -227,7 +227,8 @@
                     )
                 }
                 try {
-                    WindowManagerGlobal.getWindowManagerService().lockNow(/* options= */ null)
+                    checkNotNull(WindowManagerGlobal.getWindowManagerService())
+                        .lockNow(/* options= */ null)
                 } catch (e: RemoteException) {
                     Log.e(
                         TAG,