[build] Distribute wpimath protobuf headers (#5925)

wpimath/build.gradle

@@ -20,8 +20,14 @@ cppHeadersZip {
     from('src/main/native/thirdparty/gcem/include') {
         into '/'
     }
+    from("$buildDir/generated/source/proto/main/cpp") {
+        into '/wpimath/protobuf'
+        include '*.h'
+    }
 }
 
+cppHeadersZip.dependsOn generateProto
+
 model {
     components {
         all {