Support fixed-size arrays in the NDK backend

Fixed-size arrays are represented with std::array<T,N>.

An example added to golden_output.

Bug: 207087196
Test: aidl_integration_test
Test: golden_test.sh check
Change-Id: I8df11f1c29f57a527422014792edc5d6346110b9
diff --git a/aidl_language.h b/aidl_language.h
index 1eb2737..35a0215 100644
--- a/aidl_language.h
+++ b/aidl_language.h
@@ -437,7 +437,9 @@
   bool IsResolved() const { return fully_qualified_name_ != ""; }
 
   bool IsArray() const { return array_.has_value(); }
-
+  bool IsDynamicArray() const {
+    return array_.has_value() && std::get_if<DynamicArray>(&*array_) != nullptr;
+  }
   bool IsFixedSizeArray() const {
     return array_.has_value() && std::get_if<FixedSizeArray>(&*array_) != nullptr;
   }