Fix video continuity

Fixes "pixelation" seen after seeking in Netflix.
b/7211673

Change-Id: Id675acaef1e5fd7151fdfa7bd79e2f25990e1ecd
diff --git a/media/libstagefright/mpeg2ts/ATSParser.cpp b/media/libstagefright/mpeg2ts/ATSParser.cpp
index d988356..27c7bf4 100644
--- a/media/libstagefright/mpeg2ts/ATSParser.cpp
+++ b/media/libstagefright/mpeg2ts/ATSParser.cpp
@@ -592,6 +592,8 @@
 
 void ATSParser::Stream::signalDiscontinuity(
         DiscontinuityType type, const sp<AMessage> &extra) {
+    mExpectedContinuityCounter = -1;
+
     if (mQueue == NULL) {
         return;
     }