Merge "Fail check-boot-jars if boot jar contains 0 .class files" into rvc-dev am: c5fd7066 am: 9f58d772 am: 734da4e9

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

Change-Id: I79496d24ceb9d59574933a2432963d04ae6ca3aa