Improve Lottie rendering

[jrodbx]

After a pairing session with @gpeal at Droidcon NYC back in 2019, he filed https://github.com/cashapp/paparazzi/issues/110 highlighting shortcomings in layoutlib/paparazzi from rendering certain Lotttie animation/view configurations.

The recent move to native layoutlib is an improvement, but masks.json still doesn't render quite correctly.

To repro, checkout jrod/2019-08-28/lottie, then run:

./gradlew paparazzi-gradle-plugin:test --tests=app.cash.paparazzi.gradle.PaparazziPluginTest.lottie

and examine the output files in:

paparazzi-gradle-plugin/src/test/projects/lottie/build/reports/paparazzi/images

comparing them to the two jsons provided in the branch when rendered here: https://lottiefiles.com/tools/json-editor