Fail early when CharSequence is used in c++ or ndk

Fixes: 147441847
Test: aidl_parser_fuzzer w/ the test case
Change-Id: I8da7e5d4ee267777eecabf7eeb51e4fc3cb9520b
diff --git a/aidl_language.cpp b/aidl_language.cpp
index e0769bd..041f08b 100644
--- a/aidl_language.cpp
+++ b/aidl_language.cpp
@@ -769,9 +769,9 @@
       }
     }
   }
-  if (this->GetName() == "Map") {
+  if (this->GetName() == "Map" || this->GetName() == "CharSequence") {
     if (lang != Options::Language::JAVA) {
-      AIDL_ERROR(this) << "Currently, only Java backend supports Map.";
+      AIDL_ERROR(this) << "Currently, only Java backend supports " << this->GetName() << ".";
       return false;
     }
   }