Merge "Make common signature system property definitions optional" into main...

Merge "Make common signature system property definitions optional" into main am: b8306086 am: e728051f am: 13ba580f am: 20dbd142 am: 8dcb5a09 am: 47da6d45

Original change: https://android-review.googlesource.com/c/platform/build/+/2609473



Change-Id: I719e2b6b35094964888137c687deb5045b3d2e11
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>