Unity Android & C# style updates

Updates for Unity:
- Android support with OpenGL
- C# linting including formatting errors
  -  This brings our code style in line with C#'s standards, even though it unfortunately varies from our Dart and C++ one.

Note that the formatting (camel case) changes are breaking changes for anyone using the Rive package (we'll need to update the demos/examples repo).

Diffs=
231b35a41 Unity Android & C# style updates (#6517)

Co-authored-by: Luigi Rosso <luigi-rosso@users.noreply.github.com>

.rive_head

diff --git a/.rive_head b/.rive_head
index 3eb8c18..1d4a985 100644
--- a/.rive_head
+++ b/.rive_head
@@ -1 +1 @@
-da8d2d5f7f2bc943561676e8d0c282a8725fee15
+231b35a4130d96ee9be540f51b82c0ef831bad91

include/rive/layout.hpp

diff --git a/include/rive/layout.hpp b/include/rive/layout.hpp
index 3be95f0..afd21ab 100644
--- a/include/rive/layout.hpp
+++ b/include/rive/layout.hpp
@@ -15,14 +15,12 @@
 
 class Alignment
 {
-private:
-    float m_X, m_Y;
-
 public:
-    Alignment(float x, float y) : m_X(x), m_Y(y) {}
+    Alignment(float x, float y) : m_x(x), m_y(y) {}
+    Alignment() : m_x(0.0f), m_y(0.0f) {}
 
-    float x() const { return m_X; }
-    float y() const { return m_Y; }
+    float x() const { return m_x; }
+    float y() const { return m_y; }
 
     static const Alignment topLeft;
     static const Alignment topCenter;
@@ -33,6 +31,9 @@
     static const Alignment bottomLeft;
     static const Alignment bottomCenter;
     static const Alignment bottomRight;
+
+private:
+    float m_x, m_y;
 };
 
 } // namespace rive