Fix for disappearing background in buttons.

Change-Id: I7c7058ee8a292e73c25ba8c3e8d46899b7296c1e
diff --git a/core/java/android/widget/TextView.java b/core/java/android/widget/TextView.java
index aefe8d8..f32ae92 100644
--- a/core/java/android/widget/TextView.java
+++ b/core/java/android/widget/TextView.java
@@ -6206,7 +6206,10 @@
             if (applyTransformation) {
                 setTransformationMethod(null);
             }
-            setBackgroundDrawable(mEditTextMultilineBackground);
+            // mEditTextMultilineBackground is defined and used only in EditText
+            if (mEditTextMultilineBackground != null) {
+                setBackgroundDrawable(mEditTextMultilineBackground);
+            }
         }
     }