Add METADATA to nanopb-c: BSD+Apache2+zlib+MIT=NOTICE am: e1a745d93b

Change-Id: Ib4b647b60a73f9d85f9c327ef40b27153136614a
diff --git a/METADATA b/METADATA
new file mode 100644
index 0000000..d97975c
--- /dev/null
+++ b/METADATA
@@ -0,0 +1,3 @@
+third_party {
+  license_type: NOTICE
+}