Fix media_cas_proxy_sdk build issue.

Add example binary for testing building the SDK after 'git clone' from our repo.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=227583629

protos/public/verified_media_pipeline.proto

@@ -0,0 +1,39 @@
+////////////////////////////////////////////////////////////////////////////////
+// Copyright 2017 Google LLC.
+//
+// This software is licensed under the terms defined in the Widevine Master
+// License Agreement. For a copy of this agreement, please contact
+// widevine-licensing@google.com.
+////////////////////////////////////////////////////////////////////////////////
+//
+// Description:
+//   Protocol messages used for the Verified Media Pipeline feature of the
+//   Widevine CDM.
+
+syntax = "proto2";
+
+option optimize_for = LITE_RUNTIME;
+
+package vmp;
+
+message VmpData {
+  message SignedBinaryInfo {
+    // File name of the binary. Required.
+    optional string file_name = 1;
+    // Index into |certificates| for the code signing certificate used to sign
+    // this binary. Required if the binary is signed..
+    optional uint32 certificate_index = 2;
+    // SHA-512 digest of signed binary. Required if the file was present.
+    optional bytes binary_hash = 3;
+    // Flags from signature file, if any. Required if signed.
+    optional uint32 flags = 4;
+    // Signature of the binary. Required if signed.
+    optional bytes signature = 5;
+  }
+
+  // Distinct certificates used in binary code signing. No certificate should
+  // be present more than once.
+  repeated bytes certificates = 1;
+  // Info about each signed binary.
+  repeated SignedBinaryInfo signed_binary_info = 2;
+}