Only use the pre-animation bounds when an animation is running and is set

- Fix issue with NaN being calculated as the saved fraction due to the wrong
  bounds being used

Bug: 109841835
Test: atest CtsActivityManagerDeviceTestCases:ActivityManagerPinnedStackTests
Test: Repeatedly launch pip into fullscreen landscape app, and ensure that
      the saved snapfraction is calculated correctly

Change-Id: I9b442cda636121164af1f3e66050894d06518439

services/core/java/com/android/server/wm/AppWindowToken.java

@@ -1334,8 +1334,20 @@ class AppWindowToken extends WindowToken implements WindowManagerService.AppFree
             // for the next re-entry into PiP (assuming the activity is not hidden or destroyed)
             final TaskStack pinnedStack = mDisplayContent.getPinnedStack();
             if (pinnedStack != null) {
+                final Rect stackBounds;
+                if (pinnedStack.lastAnimatingBoundsWasToFullscreen()) {
+                    // We are animating the bounds, use the pre-animation bounds to save the snap
+                    // fraction
+                    stackBounds = pinnedStack.mPreAnimationBounds;
+                } else {
+                    // We skip the animation if the fullscreen configuration is not compatible, so
+                    // use the current bounds to calculate the saved snap fraction instead
+                    // (see PinnedActivityStack.skipResizeAnimation())
+                    stackBounds = mTmpRect;
+                    pinnedStack.getBounds(stackBounds);
+                }
                 mDisplayContent.mPinnedStackControllerLocked.saveReentrySnapFraction(this,
-                        pinnedStack.mPreAnimationBounds);
+                        stackBounds);
             }
         }
     }

services/core/java/com/android/server/wm/PinnedStackController.java

@@ -589,6 +589,7 @@ class PinnedStackController {
         pw.println(prefix + "  mImeHeight=" + mImeHeight);
         pw.println(prefix + "  mIsShelfShowing=" + mIsShelfShowing);
         pw.println(prefix + "  mShelfHeight=" + mShelfHeight);
+        pw.println(prefix + "  mReentrySnapFraction=" + mReentrySnapFraction);
         pw.println(prefix + "  mIsMinimized=" + mIsMinimized);
         if (mActions.isEmpty()) {
             pw.println(prefix + "  mActions=[]");
@@ -601,6 +602,7 @@ class PinnedStackController {
             }
             pw.println(prefix + "  ]");
         }
+        pw.println(prefix + " mDisplayInfo=" + mDisplayInfo);
     }
 
     void writeToProto(ProtoOutputStream proto, long fieldId) {