Add a VerifierDeps::Dump method.

Also, fix the Encode/Decode logic around dex file order:
iterating over a std::map doesn't guarantee insertion order.

test: verifier_deps_test
bug: 30937355

Change-Id: Id3efd703b3c8ca21ab49c2600c612c132fb021cd
diff --git a/build/Android.gtest.mk b/build/Android.gtest.mk
index 4f273e5..c785bef 100644
--- a/build/Android.gtest.mk
+++ b/build/Android.gtest.mk
@@ -105,7 +105,7 @@
 ART_GTEST_stub_test_DEX_DEPS := AllFields
 ART_GTEST_transaction_test_DEX_DEPS := Transaction
 ART_GTEST_type_lookup_table_test_DEX_DEPS := Lookup
-ART_GTEST_verifier_deps_test_DEX_DEPS := VerifierDeps
+ART_GTEST_verifier_deps_test_DEX_DEPS := VerifierDeps MultiDex
 
 # The elf writer test has dependencies on core.oat.
 ART_GTEST_elf_writer_test_HOST_DEPS := $(HOST_CORE_IMAGE_optimizing_no-pic_64) $(HOST_CORE_IMAGE_optimizing_no-pic_32)