Arrays in .hal files are now exposed to C++ as hidl_array<T, SIZE ...>

instead of as native arrays. This allows them to be copied which in turn lets
them exist in vectors. In the Java backend, vectors are limited to
one-dimensional arrays and scalar arrays are properly wrapped,
i.e. vec<uint8_t[]> => Vector<Byte[]>

Change-Id: I47524ec8423dfb41a436df36af8fa05eb8b3c0cc
Bug: 31682327
Test: hidl_test and hidl_test_java
diff --git a/generateJava.cpp b/generateJava.cpp
index a5bdce6..b6d1d0d 100644
--- a/generateJava.cpp
+++ b/generateJava.cpp
@@ -107,7 +107,9 @@
     if (!isJavaCompatible()) {
         fprintf(stderr,
                 "ERROR: This interface is not Java compatible. The Java backend"
-                " does NOT support union types or native handles.\n");
+                " does NOT support union types nor native handles. "
+                "In addition, vectors of arrays are limited to at most "
+                "one-dimensional arrays.\n");
 
         return UNKNOWN_ERROR;
     }