Add a workaround for simulate secondary display

To workaround a deadlock caused by bufferqueue locks
we force RenderThread over to use async mode which
we enable via eglSwapInterval(0)

Bug: 38372997
Test: steps in the bug
Change-Id: Ia305f73abbdd64ab0c25d1f7d32792cc6295a0ce
diff --git a/libs/hwui/renderthread/EglManager.cpp b/libs/hwui/renderthread/EglManager.cpp
index 44af5fd..ed30708 100644
--- a/libs/hwui/renderthread/EglManager.cpp
+++ b/libs/hwui/renderthread/EglManager.cpp
@@ -279,6 +279,9 @@
         }
     }
     mCurrentSurface = surface;
+    if (Properties::disableVsync) {
+        eglSwapInterval(mEglDisplay, 0);
+    }
     return true;
 }