Fix screenshot not showing up on subsequent screenshots

The static screenshot view wasn't getting set back to alpha=1 on
reset, so it was effectively invisible. This change resets it and
returns to animating out the background protection.

Bug: 219790596
Fix: 219790596
Test: manual; observed taking screenshots in quick succession (while
the screenshot was animating out) to see that the alpha wasn't reset,
and was after the change

Change-Id: I3afc4e97fd1cd28a1cf9988be0c519590dca7b30
(cherry picked from commit 163d76a7ea)

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

@@ -403,12 +403,20 @@ public class ScreenshotView extends FrameLayout implements
                     }
 
                     @Override
-                    public void onSwipeDismissInitiated(Animator animator) {
+                    public void onSwipeDismissInitiated(Animator anim) {
                         if (DEBUG_DISMISS) {
                             Log.d(ScreenshotView.TAG, "dismiss triggered via swipe gesture");
                         }
                         mUiEventLogger.log(ScreenshotEvent.SCREENSHOT_SWIPE_DISMISSED, 0,
                                 mPackageName);
+                        anim.addListener(new AnimatorListenerAdapter() {
+                            @Override
+                            public void onAnimationStart(Animator animation) {
+                                super.onAnimationStart(animation);
+                                mBackgroundProtection.animate()
+                                        .alpha(0).setDuration(anim.getDuration()).start();
+                            }
+                        });
                     }
 
                     @Override
@@ -999,6 +1007,7 @@ public class ScreenshotView extends FrameLayout implements
         mSmartChips.clear();
         mQuickShareChip = null;
         setAlpha(1);
+        mScreenshotStatic.setAlpha(1);
         mScreenshotSelectorView.stop();
     }