Fix NPE in BubbleTextView

- Icon can be null when we use BTV for text only

Bug: 223809081
Test: manual
Change-Id: I9efd8e4b420127beb249b20e71ae37c359bb6467
diff --git a/src/com/android/launcher3/BubbleTextView.java b/src/com/android/launcher3/BubbleTextView.java
index 041bee9..3bc0f6d 100644
--- a/src/com/android/launcher3/BubbleTextView.java
+++ b/src/com/android/launcher3/BubbleTextView.java
@@ -867,6 +867,11 @@
     }
 
     protected void applyCompoundDrawables(Drawable icon) {
+        if (icon == null) {
+            // Icon can be null when we use the BubbleTextView for text only.
+            return;
+        }
+
         // If we had already set an icon before, disable relayout as the icon size is the
         // same as before.
         mDisableRelayout = mIcon != null;