Set background color for emoji category tabs.

Bug: 19686516.
Change-Id: I519d09491ded4f5d85a5951afb48a9638b5fe652
diff --git a/java/src/com/android/inputmethod/keyboard/emoji/EmojiPalettesView.java b/java/src/com/android/inputmethod/keyboard/emoji/EmojiPalettesView.java
index f4c4f1a..a3b869d 100644
--- a/java/src/com/android/inputmethod/keyboard/emoji/EmojiPalettesView.java
+++ b/java/src/com/android/inputmethod/keyboard/emoji/EmojiPalettesView.java
@@ -151,6 +151,9 @@
         tspec.setContent(R.id.emoji_keyboard_dummy);
         final ImageView iconView = (ImageView)LayoutInflater.from(getContext()).inflate(
                 R.layout.emoji_keyboard_tab_icon, null);
+        // TODO: Replace background color with its own setting rather than using the
+        //       category page indicator background as a workaround.
+        iconView.setBackgroundColor(mCategoryPageIndicatorBackground);
         iconView.setImageResource(mEmojiCategory.getCategoryTabIcon(categoryId));
         iconView.setContentDescription(mEmojiCategory.getAccessibilityDescription(categoryId));
         tspec.setIndicator(iconView);