Merge "launcher: correct page spacing for multiple panels" into sc-v2-dev am: 496ca0081e am: 016ba91625

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/15337415

Change-Id: Ibc5d0f65082b8130cbadb362d54272a21b714989