Separate vdex versioning into two sections: verifier deps and dex code.

The layout is still the same, but this CL allows updating the cdex and
quickening encoding versions without having to update the verifier deps
version.

bug: 63920015
Test: test.py, dex2oat_test, oat_writer_test, oatdump_test

(cherry picked from commit 3a29355967f29999ba81b5772ec66d3ddee9ce3e)

Change-Id: I1b5b2cab30af18ab6ff2df6119913525330bec3c
diff --git a/runtime/oat_file_assistant.cc b/runtime/oat_file_assistant.cc
index 5888c37..38ca4c9 100644
--- a/runtime/oat_file_assistant.cc
+++ b/runtime/oat_file_assistant.cc
@@ -408,7 +408,7 @@
     return true;
   }
 
-  uint32_t number_of_dex_files = file.GetHeader().GetNumberOfDexFiles();
+  uint32_t number_of_dex_files = file.GetVerifierDepsHeader().GetNumberOfDexFiles();
   if (required_dex_checksums->size() != number_of_dex_files) {
     *error_msg = StringPrintf("expected %zu dex files but found %u",
                               required_dex_checksums->size(),