Set default avatar background color to white so transparent BIMIs are displayed correctly

Author: LunarX

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

@@ -30,7 +30,7 @@
         android:id="@+id/avatarImage"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
-        android:background="?android:attr/colorPrimary"
+        android:background="@color/white"
         android:contentDescription="@string/contentDescriptionUserAvatar"
         android:src="@drawable/placeholder"
         app:shapeAppearance="@style/CircleImageView"