Improve tonemapping utilities

* Add util for getting buffer dataspace from metadata, since some
  ANativeWindow queries are unreliable when Surface endpoints are passed
  between processes, e.g., camera
* Let libshaders generate SkSL for SkColorFilters

Bug: 238395777
Test: Switching HDR cameras don't color shift
Change-Id: I7c3b917eeafcf8d028f8f52f38aa1389025bc607