Merge "Pass cargo output around as string rather than writing to file." into main am: b0147248bd am: 71a2feffbb am: 65405de038

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

Change-Id: I41434f843a01ce08fbb17690a04dbb1f6cc2571b
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>