Visual Fix: Have stream arrows nicely fill & center when topic wraps to two lines

Author: niftynei

app/src/main/res/drawable/triangle.xml

@@ -7,7 +7,7 @@
     <group android:name="triableGroup">
         <path
             android:name="triangle"
-            android:fillColor="@color/stream_header"
+            android:fillColor="@color/colorAccent"
             android:pathData="M0 0 L0 0 L10 5 L0 10 Z" />
     </group>
 </vector>

app/src/main/res/layout/message_header.xml

@@ -7,34 +7,38 @@
     <TextView
         android:id="@+id/displayRecipient"
         android:layout_width="wrap_content"
-        android:layout_height="wrap_content"
+        android:layout_height="match_parent"
         android:background="@color/stream_header"
-        android:gravity="center_horizontal"
+        android:gravity="center"
         android:padding="4dp"
         android:paddingLeft="10dp"
         android:paddingStart="10dp"
         android:text="@string/stream_txt"
         android:textColor="@color/colorTextPrimary"
         android:textStyle="bold"
-        tools:text="Stream" />
+        tools:text="Short Stream"
+        tools:background="@color/colorAccent"
+        />
 
     <TextView
         android:id="@+id/sep"
         android:layout_width="wrap_content"
-        android:layout_height="wrap_content"
+        android:layout_height="match_parent"
         android:background="@drawable/triangle"
         android:padding="4dp"
-        android:text=" " />
+        android:text=" "
+        />
 
     <TextView
         android:id="@+id/instance"
         android:layout_width="0dp"
         android:layout_height="wrap_content"
         android:layout_marginLeft="7dp"
         android:layout_weight="1"
+        android:gravity="center_vertical"
         android:background="@color/messageHeaderBackground"
         android:padding="4dp"
-        android:text="@string/subject" />
+        tools:text="This is a very very very long topic that is so long that it wraps" />
 
     <ImageView
         android:id="@+id/muteMessageImage"