Import grpcio 0.6.0

And add metadata files using the following command:
get_rust_pkg.py --add3prf -v grpcio-0.6.0 -o grpcio

Test: none
Change-Id: I53cc0feb5c9d24eacb62331b968cab4ec85f60a6
diff --git a/scripts/reset-submodule.cmd b/scripts/reset-submodule.cmd
new file mode 100755
index 0000000..f873a75
--- /dev/null
+++ b/scripts/reset-submodule.cmd
@@ -0,0 +1,8 @@
+git submodule update --init grpc-sys/grpc
+cd grpc-sys/grpc
+git submodule update --init third_party/boringssl-with-bazel
+git submodule update --init third_party/cares/cares
+git submodule update --init third_party/abseil-cpp
+cd third_party/zlib
+git clean -f
+git reset --hard