[Magnifier-63] Hide it for rotated/scaled textview

The magnifier is currently behaving badly when the magnified view is
scaled and/or rotated - the content of the magnifier and its position
are wrong, as we do not take these into account when computing
coordinates for content copy and magnifier positioning. This CL is
making the magnifier remain hidden when such transformations are applied
to the magnified view or a view above it in the view hierarchy.

Bug: 112519631
Test: manual testing
Change-Id: Ibb81fdc9d2ec8ba14914166e408c92a3aad7e312