Add metadata files for plotters-backend. am: 3da56e3c5b Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/plotters-backend/+/1621410 Change-Id: I32b29f6b1a889e6d026d60e6c177eca42995352a
This is a part of plotters project. For more details, please check the following links: