Add crosvm.img prebuilt

Check in a prebuilt of Cuttlefish host tools, which include CrosVM.

Change-Id: I7b804e05d3f2edeab51acd5d68f4caf90c8f44a1
diff --git a/linux-aarch64/images/crosvm.ext4 b/linux-aarch64/images/crosvm.ext4
new file mode 100644
index 0000000..6e04424
--- /dev/null
+++ b/linux-aarch64/images/crosvm.ext4
Binary files differ