Allow SurfaceView's Surface to be preserved on visibility changes

TextureView preserves the resources for its SurfaceTexture between
visibility changes, only releasing them when the TextureView has been
detached from the window. SurfaceView, in contrast, destroys its
underlying Surface when the view is no longer visible.

This imposes some challenges in a use-case around scrolling videos.
TextureView is somewhat more efficient in managing codec and Surface
resources, since an application could set up the codec ahead of time
before committing to immediate playback. An application could also more
easily reuse resources when scrolling between two of the same video.

To resolve this, add a mode to SurfaceView that allows for retaining the
Surface when visibility changes. This means that the Surface would only
be cleaned up when the SurfaceView is detached from the window, which
mirrors TextureView's default lifecycle. Then, scrolling between two
videos is easy, since off-screen SurfaceViews can just be hidden in the
layout.

Bug: 241567563
Test: SurfaceViewTests
Test: Hacked build to test on existing apps
Change-Id: Ie873d7733445ddf543bba0745bbfdca1b5b8ae1f