Merge "Fail check-boot-jars if boot jar contains 0 .class files" into rvc-dev am: c5fd7066 am: b96c9c35 am: 30ae5608

Original change: https://googleplex-android-review.googlesource.com/c/platform/build/+/11895739

Change-Id: I7356ca885e695abffebb8b6eb12e291c2770a7fc