Update libjpeg-turbo to 1.5.3

Bug: 70203010
Test: Existing tests

Use commit at tag 1.5.3 (bf6c774305c9feb30cff7b99e1a475df61bfa008).

This includes a fix for decompressing grayscale JPEG images that were
compressed with a sampling factor other than 1 (b/70203010). The bug
manifested as black stripes appearing when using the region decoder.

ChangeLog.md contains more detailed changes.

Add -Wno-sign-compare to Android.bp to silence a warning in jmemnobs.c.

Change-Id: Ifefc70073fdff9c68e9b2cbcddf114c8bcb7d366
diff --git a/jpegtran.c b/jpegtran.c
index c44f21e..6f8fd5b 100644
--- a/jpegtran.c
+++ b/jpegtran.c
@@ -4,7 +4,7 @@
  * This file was part of the Independent JPEG Group's software:
  * Copyright (C) 1995-2010, Thomas G. Lane, Guido Vollbeding.
  * libjpeg-turbo Modifications:
- * Copyright (C) 2010, 2014, D. R. Commander.
+ * Copyright (C) 2010, 2014, 2017, D. R. Commander.
  * For conditions of distribution and use, see the accompanying README.ijg
  * file.
  *
@@ -90,7 +90,7 @@
   fprintf(stderr, "  -version       Print version information and exit\n");
   fprintf(stderr, "Switches for wizards:\n");
 #ifdef C_MULTISCAN_FILES_SUPPORTED
-  fprintf(stderr, "  -scans file    Create multi-scan JPEG per script file\n");
+  fprintf(stderr, "  -scans FILE    Create multi-scan JPEG per script FILE\n");
 #endif
   exit(EXIT_FAILURE);
 }