only update recent emoji on other pages

Closes #3208
// FREEBIE

src/org/thoughtcrime/securesms/components/emoji/StaticEmojiPageModel.java

@@ -3,7 +3,7 @@ package org.thoughtcrime.securesms.components.emoji;
 import android.support.annotation.DrawableRes;
 import android.support.annotation.NonNull;
 
-public class StaticEmojiPageModel extends EmojiPageModel {
+public class StaticEmojiPageModel implements EmojiPageModel {
   @DrawableRes private final int   icon;
   @NonNull     private final int[] codePoints;
 
@@ -19,4 +19,8 @@ public class StaticEmojiPageModel extends EmojiPageModel {
   @NonNull public int[] getCodePoints() {
     return codePoints;
   }
+
+  @Override public boolean isDynamic() {
+    return false;
+  }
 }