Merge "Pass cargo output around as string rather than writing to file." into main am: b0147248bd

Original change: https://android-review.googlesource.com/c/platform/development/+/2843614

Change-Id: I9f9caae120b4d757c89f278fbc59baaf26dee395
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>