increase threshold value

Bug: b/121103837
Test: Cts test android.media.cts.VpxEncoderTest#testAsyncEncodingVP8
Change-Id: I34ff5226e04d1d3383c1c2bdc4515d50ea06a1fa
diff --git a/tests/tests/media/src/android/media/cts/VpxEncoderTest.java b/tests/tests/media/src/android/media/cts/VpxEncoderTest.java
index 38a8403..6ef2a65 100644
--- a/tests/tests/media/src/android/media/cts/VpxEncoderTest.java
+++ b/tests/tests/media/src/android/media/cts/VpxEncoderTest.java
@@ -67,7 +67,7 @@
     // Maximum allowed average PSNR difference of the encoder running in a looper thread with 0 ms
     // buffer dequeue timeout comparing to the encoder running in a callee's thread with 100 ms
     // buffer dequeue timeout.
-    private static final double MAX_ASYNC_AVERAGE_PSNR_DIFFERENCE = 0.5;
+    private static final double MAX_ASYNC_AVERAGE_PSNR_DIFFERENCE = 1.5;
     // Maximum allowed minimum PSNR difference of the encoder running in a looper thread
     // comparing to the encoder running in a callee's thread.
     private static final double MAX_ASYNC_MINIMUM_PSNR_DIFFERENCE = 2;