[pip] PictureInPictureWindowManager and test fixes for wayland

Make the following changes for platforms (e.g. ozone/wayland) that don't
support global screen coordinates:
- Do not set an initial position of the window in`PictureInPictureWindowManager`.
- Since the test `RespectsUserLocationChangesAfterChildDialogCloses` is specific to client-initiated window location changes, GTEST_SKIP it.
- Do not assert the point in screen coordinates in `PictureInPictureBrowserFrameViewTest.TestAnimationTiming`.
- Skip similar global screen coordinate dependencies in PiP
browser_tests

Fixed: 405327469
Bug: 391903220

Change-Id: Ib45b28b2b49b18827ea9a113a92ecd7c43e638d1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6361341
Reviewed-by: Tommy Steimel <steimel@chromium.org>
Commit-Queue: Orko Garai <orko@igalia.com>
Reviewed-by: Elly FJ <ellyjones@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1436911}