make copyTo_with_allocator android only

Bug: skia:6464

Change-Id: I3d95daae2ae854671e6231e62f200913ce3586d0
Reviewed-on: https://skia-review.googlesource.com/11486
Commit-Queue: Mike Reed <reed@google.com>
Reviewed-by: Matt Sarett <msarett@google.com>
3 files changed