Merge "pixel3_mainline: Add changes to get pixel3_mainline building a boot.img (v3)" am: 679c9c12f8 am: 7e7b7b22b5

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

Change-Id: I078b9cf0bf73f7a591396346dbbb2729f6ac1c4c