Fix existing native samples to follow our style guide

There is no standard for our native code sample. It would be perceived as more professional if all code sample follows modern style.

### In Scope
* Avoid C-ism in C++ and vice versa
* Code for easy reading
* Reflect knowledge regarding good practice

### Not In Scope
* Bracket position
* Space in parenthesis
* Tab vs space
* etc.

### Possible Solution
Let's propose to use the [Google C++ Style Guide](https://google.github.io/styleguide/cppguide.html) as it's well written, has `clang-format` support, and minimum maintenance for us. The 2 modifications proposed, to align it more to our Java coding style, are 4 space indentation and allow exceptions to be used.

The issue does not name files, tests, or entry points, so first locate all existing native code samples in the repository and identify which are C versus C++. Read the Google C++ Style Guide and review the proposed four-space indentation and exception rules. Done means the samples consistently follow the agreed style while excluding the explicitly out-of-scope formatting details.

Written by the indexing model from the issue text.