MTP: Implement GetThumb command

This allows the PC to access thumbnails in JPEG files over MTP/PTP

Bug: 3219495

Change-Id: I4964f8b4826dffb7f0f77464ec91bd2e97a2f007
Signed-off-by: Mike Lockwood <lockwood@android.com>
diff --git a/media/mtp/MtpDataPacket.h b/media/mtp/MtpDataPacket.h
index 577cea1..8a08948 100644
--- a/media/mtp/MtpDataPacket.h
+++ b/media/mtp/MtpDataPacket.h
@@ -100,6 +100,7 @@
     // write our data to the given file descriptor
     int                 write(int fd);
     int                 writeDataHeader(int fd, uint32_t length);
+    int                 writeData(int fd, void* data, uint32_t length);
 #endif
 
 #ifdef MTP_HOST