Make sure that key frame is generated for timelapse video recording if there are at least two input video frames from camera source.

This will fix the stop failure issue where we have to wait n * time_interval before a key frame can be received by the file writer, where
 o n is the actual number of buffers advertised by the video encoder
 o time_interval is the interval settings for timelapse video recording
   specifying the time distance between neighboring input video frames

The fix includes two parts:
o OMXCodec will not submit all n buffers at one time, but instead submit one input
  frame at one time if it become available.

o Timelapse camera source made available the first two input frames and do not skip
  them so that the first compressed output frame data can be received regardless
  the specified time_interval

bug - 3367659

Change-Id: Ia68cc2cb0d71aa7dc54540e9ad82fae911ad530b
diff --git a/media/libstagefright/CameraSource.cpp b/media/libstagefright/CameraSource.cpp
index b1c6b18..66e0657 100644
--- a/media/libstagefright/CameraSource.cpp
+++ b/media/libstagefright/CameraSource.cpp
@@ -147,8 +147,8 @@
       mNumFramesReceived(0),
       mLastFrameTimestampUs(0),
       mStarted(false),
-      mFirstFrameTimeUs(0),
       mNumFramesEncoded(0),
+      mFirstFrameTimeUs(0),
       mNumFramesDropped(0),
       mNumGlitches(0),
       mGlitchDurationThresholdUs(200000),