Merge "Allow the host to send empty clipboards to the guest" am: d20bc58ae9

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/2415825

Change-Id: I8b6ec791f558933f3111006d26e6d651785267eb
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>