Update currentConfig variable when active display is changed.

Bug: 17182607
Change-Id: I8631c105a9e0fa402a7d9670717becc9857af935
diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.cpp b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
index 53409d1..e67b2e7 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.cpp
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
@@ -780,6 +780,8 @@
 
 status_t HWComposer::setActiveConfig(int disp, int mode) {
     LOG_FATAL_IF(disp >= VIRTUAL_DISPLAY_ID_BASE);
+    DisplayData& dd(mDisplayData[disp]);
+    dd.currentConfig = mode;
     if (mHwc && hwcHasApiVersion(mHwc, HWC_DEVICE_API_VERSION_1_4)) {
         return (status_t)mHwc->setActiveConfig(mHwc, disp, mode);
     } else {