Kotlin: Use correct cast for string type

The existing cast method gives lint warnings.

Change-Id: I7241119400c6a84058d0be8808a07cdcb8920124
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/197643
Commit-Queue: Jim Blackler <jimblackler@google.com>
Reviewed-by: Sonakshi Saxena <nexa@google.com>
diff --git a/generator/templates/art/structures.cpp b/generator/templates/art/structures.cpp
index a57fb37..bfb14db 100644
--- a/generator/templates/art/structures.cpp
+++ b/generator/templates/art/structures.cpp
@@ -47,7 +47,7 @@
                 if (mObj) {
                     //* TODO(b/330293719): free associated resources.
                     converted->{{ member.name.camelCase() }} =
-                            env->GetStringUTFChars(static_cast<jstring>(mObj), 0);
+                            env->GetStringUTFChars(reinterpret_cast<jstring>(mObj), 0);
                 }
             }
             {% elif member.constant_length == 1 %} {