Releasing the former Stadia file transfer tools

The tools allow efficient and fast synchronization of large directory
trees from a Windows workstation to a Linux target machine.

cdc_rsync* support efficient copy of files by using content-defined
chunking (CDC) to identify chunks within files that can be reused.

asset_stream_manager + cdc_fuse_fs support efficient streaming of a
local directory to a remote virtual file system based on FUSE. It also
employs CDC to identify and reuse unchanged data chunks.

tools/BUILD

@@ -0,0 +1,8 @@
+package(default_visibility = ["//visibility:public"])
+
+config_setting(
+    name = "windows",
+    values = {
+        "cpu": "x64_windows",
+    },
+)