Move UdevDecodeString from media/midi to device/udev_linux

device/BUILD.gn

Index: device/BUILD.gn
diff --git a/device/BUILD.gn b/device/BUILD.gn
index 5dc6654047fcd77996fda9f1ced864c952b4f9f9..9c684ebbc895de1955c88efd27b227dbb179d28a 100644
--- a/device/BUILD.gn
+++ b/device/BUILD.gn
@@ -86,6 +86,12 @@ test("device_unittests") {
     libs = [ "IOBluetooth.framework" ]
   }
 
+  if (use_udev) {
+    sources += [ "udev_linux/udev_unittest.cc" ]
+
+    deps += [ "//device/udev_linux" ]
+  }
+
   if (is_linux && !use_udev) {
     # Udev is the only Linux implementation. If we're compiling without Udev,
     # disable these unittests.