Merge "pixel3_mainline: Add changes to get pixel3_mainline building a boot.img (v3)" am: 679c9c12f8

Original change: https://android-review.googlesource.com/c/device/linaro/dragonboard/+/1354425

Change-Id: Ib7308ac4b3481ccf9aeeaa046728589f2c4aa4f5