Go back to previous state when hitting back from discovery bounce

Normally when you hit back, we just close the floating view if there
is one. This makes less sense for DiscoveryBounce, since it doesn't
feel like a different state even though it's technically a floating
view. So in that case, don't consume the back press; let launcher
handle it to go to the previous state.

Bug: 80075741
Change-Id: I7270b61be70509cb2101400a12929478a5d082aa

src/com/android/launcher3/AbstractFloatingView.java

@@ -121,9 +121,11 @@ public abstract class AbstractFloatingView extends LinearLayout implements Touch
 
     protected abstract boolean isOfType(@FloatingViewType int type);
 
-    public void onBackPressed() {
+    /** @return Whether the back is consumed. If false, Launcher will handle the back as well. */
+    public boolean onBackPressed() {
         logActionCommand(Action.Command.BACK);
         close(true);
+        return true;
     }
 
     @Override

src/com/android/launcher3/Launcher.java

@@ -1583,8 +1583,8 @@ public class Launcher extends BaseDraggingActivity
         // by using if-else statements.
         UserEventDispatcher ued = getUserEventDispatcher();
         AbstractFloatingView topView = AbstractFloatingView.getTopOpenView(this);
-        if (topView != null) {
-            topView.onBackPressed();
+        if (topView != null && topView.onBackPressed()) {
+            // Handled by the floating view.
         } else if (!isInState(NORMAL)) {
             LauncherState lastState = mStateManager.getLastState();
             ued.logActionCommand(Action.Command.BACK, mStateManager.getState().containerType,

src/com/android/launcher3/allapps/DiscoveryBounce.java

@@ -83,6 +83,14 @@ public class DiscoveryBounce extends AbstractFloatingView {
         }
     }
 
+    @Override
+    public boolean onBackPressed() {
+        super.onBackPressed();
+        // Go back to the previous state (from a user's perspective this floating view isn't
+        // something to go back from).
+        return false;
+    }
+
     @Override
     public boolean onControllerInterceptTouchEvent(MotionEvent ev) {
         handleClose(false);

src/com/android/launcher3/folder/Folder.java

@@ -1437,12 +1437,13 @@ public class Folder extends AbstractFloatingView implements DragSource,
     }
 
     @Override
-    public void onBackPressed() {
+    public boolean onBackPressed() {
         if (isEditingName()) {
             mFolderName.dispatchBackKey();
         } else {
             super.onBackPressed();
         }
+        return true;
     }
 
     @Override