IDEA-84070 fix '@null' red code in android xml files

plugins/android/src/org/jetbrains/android/dom/converters/ResourceReferenceConverter.java

@@ -314,6 +314,10 @@ public class ResourceReferenceConverter extends ResolvingConverter<ResourceValue
 
   @NotNull
   public PsiReference[] createReferences(GenericDomValue<ResourceValue> value, PsiElement element, ConvertContext context) {
+    if ("@null".equals(value.getStringValue())) {
+      return PsiReference.EMPTY_ARRAY;
+    }
+
     Module module = context.getModule();
     if (module != null) {
       AndroidFacet facet = AndroidFacet.getInstance(module);

plugins/android/testData/dom/layout/hl.xml

@@ -9,6 +9,7 @@
         android:layout_height="wrap_content"
         android:layout_marginBottom="10dip"
         android:text="@string/welcome"
+        android:padding="@null"
     />
 
     <TextView
@@ -16,6 +17,7 @@
           android:layout_height="wrap_content"
           android:layout_marginBottom="10dip"
           android:text="<error>@string/animation_1_instructions</error>"
+          android:padding="<error>@nul</error>"
       />
 
   <RadioGroup android:layout_width="fill_parent" android:layout_height="wrap_content"/>