Adding google license header to source files

This was done automatically using this script:

https://github.com/google/addlicense

```
go get -u github.com/google/addlicense
$HOME/go/bin/addlicense -c "Google LLC" -l apache .
```

Manually added the license headers to meson.build files as well

Signed-off-by: Brandon Kim <brandonkim@google.com>
Change-Id: I7a17364912c8af2317a1d47a4222f7b3bdc5dc98
diff --git a/metrics-ipmi-blobs/util.hpp b/metrics-ipmi-blobs/util.hpp
index 33ed997..d3c6f24 100644
--- a/metrics-ipmi-blobs/util.hpp
+++ b/metrics-ipmi-blobs/util.hpp
@@ -1,3 +1,17 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 #pragma once
 
 #include <string>