Upgrade mtools to 3.0.37

This version contains a fix for -Wstring-concatenation error.

Test: presubmit
Bug: 175068488
Change-Id: Id4f2ae49da91a481ab2625fdf17668689b640794
diff --git a/Android.bp b/Android.bp
index a934f94..2466b88 100644
--- a/Android.bp
+++ b/Android.bp
@@ -40,29 +40,30 @@
         "codepages.c",
         "config.c",
         "copyfile.c",
+        "device.c",
         "devices.c",
         "dirCache.c",
         "directory.c",
         "direntry.c",
+        "dos2unix.c",
         "expand.c",
         "fat.c",
         "fat_free.c",
         "file.c",
         "file_name.c",
-        "filter.c",
         "floppyd_io.c",
         "force_io.c",
         "hash.c",
         "init.c",
+        "lba.c",
         "llong.c",
         "lockdev.c",
-        "match.c",
         "mainloop.c",
+        "match.c",
         "mattrib.c",
         "mbadblocks.c",
         "mcat.c",
         "mcd.c",
-        "mclasserase.c",
         "mcopy.c",
         "mdel.c",
         "mdir.c",
@@ -80,24 +81,32 @@
         "mpartition.c",
         "mshortname.c",
         "mshowfat.c",
-        "mzip.c",
         "mtools.c",
+        "mzip.c",
+        "offset.c",
         "old_dos.c",
+        "open_image.c",
+        "partition.c",
         "patchlevel.c",
         "plain_io.c",
         "precmd.c",
         "privileges.c",
+        "remap.c",
         "scsi.c",
+        "scsi_io.c",
         "signal.c",
         "stream.c",
         "streamcache.c",
         "strtonum.c",
-        "subdir.c",
-        "unixdir.c",
+        "swap.c",
         "tty.c",
+        "unix2dos.c",
+        "unixdir.c",
         "vfat.c",
         "xdf_io.c",
     ],
+    // Needs C11 language feature.
+    c_std: "experimental",
     cflags: [
         "-DSYSCONFDIR=\"/etc\"",
         "-Wno-missing-field-initializers",