Add unit tests for libdexfile external API.

This prompted a fix to ExtDexFileMakeString in the C API to make it fully
support strings with NUL chars. That's currently not expected to be
required; it's for the sake of API completeness.

Test: m test-art-{host,target}-gtest-dex_file_supp_test
Test: art/test/testrunner/run_build_test_target.py -j80 art-test
Bug: 119632407
Change-Id: Ibd3ef6e3ea7ae196f541e926a4a7665be1c91819
diff --git a/build/Android.gtest.mk b/build/Android.gtest.mk
index d95777f..00055b2 100644
--- a/build/Android.gtest.mk
+++ b/build/Android.gtest.mk
@@ -371,8 +371,8 @@
 
 ART_TEST_MODULES := \
     art_cmdline_tests \
-    art_compiler_tests \
     art_compiler_host_tests \
+    art_compiler_tests \
     art_dex2oat_tests \
     art_dexanalyze_tests \
     art_dexdiag_tests \
@@ -384,12 +384,13 @@
     art_imgdiag_tests \
     art_libartbase_tests \
     art_libdexfile_external_tests \
+    art_libdexfile_support_tests \
     art_libdexfile_tests \
     art_libprofile_tests \
     art_oatdump_tests \
     art_profman_tests \
-    art_runtime_tests \
     art_runtime_compiler_tests \
+    art_runtime_tests \
     art_sigchain_tests \
 
 ART_TARGET_GTEST_FILES := $(foreach m,$(ART_TEST_MODULES),\