ADT/GEL: Reenable config popup when switching from a device with only 1 config

Change-Id: I7f60270ffbcaae420f4da245ff3d9b271885fa37
BUG: 2218975
diff --git a/tools/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/configuration/ConfigurationComposite.java b/tools/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/configuration/ConfigurationComposite.java
index b6f9a09..1178449 100644
--- a/tools/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/configuration/ConfigurationComposite.java
+++ b/tools/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/configuration/ConfigurationComposite.java
@@ -628,10 +628,7 @@
             }
 
             mDeviceConfigs.select(0);
-            if (configNames.size() == 1) {
-                mDeviceConfigs.setEnabled(false);
-            }
-
+            mDeviceConfigs.setEnabled(configNames.size() > 1);
         }
         if (recomputeLayout) {
             onDeviceConfigChange();