Add bubble resize animation.

app/src/main/java/org/thoughtcrime/securesms/conversation/BodyBubbleLayoutTransition.kt

@@ -0,0 +1,41 @@
+package org.thoughtcrime.securesms.conversation
+
+import android.animation.LayoutTransition
+import android.animation.ValueAnimator
+import androidx.core.animation.addListener
+import androidx.recyclerview.widget.RecyclerView
+import java.lang.IllegalStateException
+
+class BodyBubbleLayoutTransition(bodyBubble: ConversationItemBodyBubble) : LayoutTransition() {
+
+  private val animator: ValueAnimator = ValueAnimator.ofFloat(0f, 1f)
+
+  init {
+    disableTransitionType(APPEARING)
+    disableTransitionType(DISAPPEARING)
+    disableTransitionType(CHANGE_APPEARING)
+    disableTransitionType(CHANGING)
+
+    setDuration(100L)
+
+    animator.duration = getAnimator(CHANGE_DISAPPEARING).duration
+    animator.addUpdateListener {
+      val parentRecycler: RecyclerView? = bodyBubble.parent.parent as? RecyclerView
+
+      try {
+        parentRecycler?.invalidateItemDecorations()
+      } catch (e: IllegalStateException) {
+        // In scroll or layout. Skip this frame.
+      }
+    }
+
+    getAnimator(CHANGE_DISAPPEARING).addListener(
+      onStart = {
+        animator.start()
+      },
+      onEnd = {
+        animator.end()
+      }
+    )
+  }
+}

app/src/main/java/org/thoughtcrime/securesms/conversation/ConversationItemBodyBubble.java

@@ -33,14 +33,17 @@ public class ConversationItemBodyBubble extends LinearLayout {
 
   public ConversationItemBodyBubble(Context context) {
     super(context);
+    setLayoutTransition(new BodyBubbleLayoutTransition(this));
   }
 
   public ConversationItemBodyBubble(Context context, @Nullable AttributeSet attrs) {
     super(context, attrs);
+    setLayoutTransition(new BodyBubbleLayoutTransition(this));
   }
 
   public ConversationItemBodyBubble(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
     super(context, attrs, defStyleAttr);
+    setLayoutTransition(new BodyBubbleLayoutTransition(this));
   }
 
   public void setOutliners(@NonNull List<Outliner> outliners) {