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/MtpServer.h b/media/mtp/MtpServer.h
index b06eb28..859a18e 100644
--- a/media/mtp/MtpServer.h
+++ b/media/mtp/MtpServer.h
@@ -133,6 +133,7 @@
     MtpResponseCode     doGetObjectPropList();
     MtpResponseCode     doGetObjectInfo();
     MtpResponseCode     doGetObject();
+    MtpResponseCode     doGetThumb();
     MtpResponseCode     doGetPartialObject(MtpOperationCode operation);
     MtpResponseCode     doSendObjectInfo();
     MtpResponseCode     doSendObject();