Rename SkPaintImageFilter to SkShaderImageFilter

Bug: skia:11230
Change-Id: I4a90191d858265e60a817aa04c3e1aacf345a7f2
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/371965
Reviewed-by: Robert Phillips <robertphillips@google.com>
7 files changed