ANDROID: fsnotify: Notify lower fs of open

If the filesystem being watched supports d_canonical_path,
notify the lower filesystem of the open as well.

Note: I've changed the Change-Id since this was previously present, but
      disappeared at some point.

Fixes: f37e0504 ("ANDROID: vfs: d_canonical_path for stacked FS")
Test: atest CtsOsTestCases:android.os.cts.FileObserverTest
Bug: 70706497
Change-Id: I7bf5c2bb2d6da18c831a8ece9ad9cf9ef3661b6b
Signed-off-by: Daniel Rosenberg <drosen@google.com>
Signed-off-by: Paul Lawrence <paullawrence@google.com>
Signed-off-by: Alessio Balsini <balsini@google.com>
(cherry picked from commit b289d170)