ImageWriter: increase timeout for BufDetachThread

To make the thread less busy.

Test: partner testing
Bug: 138352615
Change-Id: I1fe247ee33687bde450a819ace484653cf073a07
diff --git a/media/jni/android_media_ImageWriter.cpp b/media/jni/android_media_ImageWriter.cpp
index cfcba76..9e81dda 100644
--- a/media/jni/android_media_ImageWriter.cpp
+++ b/media/jni/android_media_ImageWriter.cpp
@@ -126,7 +126,7 @@
             Condition mCondition;
             std::deque<wp<Surface>> mQueue;
 
-            static const nsecs_t kWaitDuration = 20000000; // 20 ms
+            static const nsecs_t kWaitDuration = 500000000; // 500 ms
         };
         sp<DetachThread> mThread;