Merge "Cache shadow shaders for showing shadier shapes without shaky shinanigans" into sc-dev am: 3f3b607d34 am: e3fdeb8091 am: 6220230ad1

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/native/+/15189838

Change-Id: I2b10150b02d326f2ac69573f9f2b4edabb423d39