aconfig: Fix missing header in the generated c/cpp code

Test: atest aconfig.test
Change-Id: I0c23299ad366cb5c61b84b738dd9e6bf3428435c

tools/aconfig/src/codegen_cpp.rs

@@ -364,6 +364,7 @@ bool com_android_aconfig_test_enabled_rw() {
     const TEST_SOURCE_FILE_EXPECTED: &str = r#"
 #include "com_android_aconfig_test.h"
 #include <server_configurable_flags/get_flags.h>
+#include <unordered_map>
 
 namespace com::android::aconfig::test {
 

tools/aconfig/templates/cpp_source_file.template

@@ -2,6 +2,9 @@
 {{ if readwrite }}
 #include <server_configurable_flags/get_flags.h>
 {{ endif }}
+{{ if for_test }}
+#include <unordered_map>
+{{ endif }}
 
 namespace {cpp_namespace} \{