update EncoderVirtualDisplayTest to use very long i-frame interval.

- Long iframe interval is used intentionally for minimizing latency
  and it fails in some partner devices.
- This CL passes big value to fail it if not properly handled.

bug: 19520372

Change-Id: I5a8ca5bf8fe0253e85ebc023a515d68ddb403071
diff --git a/tests/tests/media/src/android/media/cts/EncodeVirtualDisplayTest.java b/tests/tests/media/src/android/media/cts/EncodeVirtualDisplayTest.java
index 12fcd30..08276fa 100755
--- a/tests/tests/media/src/android/media/cts/EncodeVirtualDisplayTest.java
+++ b/tests/tests/media/src/android/media/cts/EncodeVirtualDisplayTest.java
@@ -87,7 +87,8 @@
     // Encoder parameters.  We use the same width/height as the virtual display.
     private static final String MIME_TYPE = MediaFormat.MIMETYPE_VIDEO_AVC;
     private static int sFrameRate = 15;               // 15fps
-    private static final int IFRAME_INTERVAL = 10;    // 10 seconds between I-frames
+    // 100 days between I-frames
+    private static final int IFRAME_INTERVAL = 60 * 60 * 24 * 100;
     private static int sBitRate = 6000000;            // 6Mbps
 
     // Colors to test (RGB).  These must convert cleanly to and from BT.601 YUV.