SystemUI: Unblock gestural navigation on clearScreenshot()

If user powers screen off when partial screenshot UI is visible,
it will hide the UI but leave gestural navigation disabled.
Also the partial screenshot UI would be visible when taking a
new (normal) screenshot.

Change-Id: Ie8138bb0b771ec0e21ceb48e52872c05c946d3b4

Author: trautamaki

packages/SystemUI/src/com/android/systemui/screenshot/GlobalScreenshot.java

@@ -404,7 +404,9 @@ void handleImageAsScreenshot(Bitmap screenshot, Rect screenshotScreenBounds,
 
     void hideScreenshotSelector() {
         setLockedScreenOrientation(false);
-        mWindowManager.removeView(mScreenshotLayout);
+        if (mScreenshotLayout.getWindowToken() != null) {
+            mWindowManager.removeView(mScreenshotLayout);
+        }
         mScreenshotSelectorView.stopSelection();
         mScreenshotSelectorView.setVisibility(View.GONE);
         mCaptureButton.setVisibility(View.GONE);
@@ -1174,6 +1176,7 @@ private void clearScreenshot() {
         mActionsContainer.setTranslationY(0);
         mActionsContainerBackground.setTranslationY(0);
         mScreenshotPreview.setTranslationY(0);
+        hideScreenshotSelector();
     }
 
     private void setAnimatedViewSize(int width, int height) {