Makes some ART gtests more robust to a non-standard environment.

Two gtests (dexdump_test and dexlist_test) used to try to write
a file in the root directory and expected this operation to fail.
However, in a non-standard environment (e.g. a testing context
where such a gtest is allowed to write in `/`), these tests would
not fail as expected. Replace these paths with more explicit ones
not depending on writing permissions.

Test: Run ART gtest dexdump_test and dexlist_test in a chroot on device.
Bug: 74730596
Bug: 34729697
Change-Id: I23537757639721133d694d5366cf05d9009f05ad
diff --git a/dexdump/dexdump_test.cc b/dexdump/dexdump_test.cc
index 63e0e3f..3a2d38d 100644
--- a/dexdump/dexdump_test.cc
+++ b/dexdump/dexdump_test.cc
@@ -58,7 +58,7 @@
 
 TEST_F(DexDumpTest, CantOpenOutput) {
   std::string error_msg;
-  ASSERT_FALSE(Exec({"-o", "/joho", dex_file_}, &error_msg)) << error_msg;
+  ASSERT_FALSE(Exec({"-o", "/non/existent/path", dex_file_}, &error_msg)) << error_msg;
 }
 
 TEST_F(DexDumpTest, BadFlagCombination) {
diff --git a/dexlist/dexlist_test.cc b/dexlist/dexlist_test.cc
index 0b9adbd..68e6713 100644
--- a/dexlist/dexlist_test.cc
+++ b/dexlist/dexlist_test.cc
@@ -60,7 +60,7 @@
 
 TEST_F(DexListTest, CantOpenOutput) {
   std::string error_msg;
-  ASSERT_FALSE(Exec({"-o", "/joho", dex_file_}, &error_msg)) << error_msg;
+  ASSERT_FALSE(Exec({"-o", "/non/existent/path", dex_file_}, &error_msg)) << error_msg;
 }
 
 TEST_F(DexListTest, IllFormedMethod) {