Merge "Use empty string instead of nullable for leak report email" into udc-dev am: 3b0d3685

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23067598



Change-Id: Iebaab974f8bda94ba1a228947bafbdbccd147a04
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>