Fix wrong naming for tests in arc_file_system_watcher_util_unittest.cc

This fixes the wrong naming for AndroidSupportedMediaExtensionsSorted
and HasAndroidSupportedMediaExtension unit tests. They were incorrectly named
as ArcFileSystemWatcherServiceTest instead of ArcFileSystemWatcherUtilTest.

Bug: 1037745
Test: unit_tests --gtest_filter="Arc*"
Change-Id: I0f35fa1f976dc93743a5d20ffae5e36d9c81c8f7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1981246Reviewed-by: Naoki Fukino <fukino@chromium.org>
Commit-Queue: Umut Barış Öztunç <umutoztunc@google.com>
Cr-Commit-Position: refs/heads/master@{#727360}

chrome/browser/chromeos/arc/file_system_watcher/arc_file_system_watcher_util_unittest.cc

@@ -118,7 +118,7 @@ TEST(ArcFileSystemWatcherUtilTest, GetAndroidPath) {
                 .value());
 }
 
-TEST(ArcFileSystemWatcherServiceTest, AndroidSupportedMediaExtensionsSorted) {
+TEST(ArcFileSystemWatcherUtilTest, AndroidSupportedMediaExtensionsSorted) {
   const auto less_comparator = [](const char* a, const char* b) {
     return strcmp(a, b) < 0;
   };
@@ -128,7 +128,7 @@ TEST(ArcFileSystemWatcherServiceTest, AndroidSupportedMediaExtensionsSorted) {
       less_comparator));
 }
 
-TEST(ArcFileSystemWatcherServiceTest, HasAndroidSupportedMediaExtension) {
+TEST(ArcFileSystemWatcherUtilTest, HasAndroidSupportedMediaExtension) {
   EXPECT_TRUE(HasAndroidSupportedMediaExtension(
       base::FilePath(FILE_PATH_LITERAL("/tmp/kitten.3g2"))));
   EXPECT_TRUE(HasAndroidSupportedMediaExtension(