How to align BottomNavigationView to the bottom on an activity along with NavigationView?

Try this:

<?xml version="1.0" encoding="utf-8"?><android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:app="http://schemas.android.com/apk/res-auto"    android:layout_width="match_parent"    android:layout_height="match_parent">    <RelativeLayout        android:id="@+id/main_content"        android:layout_width="match_parent"        android:layout_height="match_parent">        <include layout="@layout/search_toolbar" />        <android.support.design.widget.BottomNavigationView            android:id="@+id/bottom_navigation_bar"            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:layout_alignParentBottom="true"            android:itemBackground="@color/colorPrimary"            app:menu="@menu/bottom_navigation" />    </RelativeLayout>    <android.support.design.widget.NavigationView        android:id="@+id/main_drawer"        android:layout_width="match_parent"        android:layout_height="match_parent"        android:layout_gravity="start"        app:headerLayout="@layout/navigation_header"        app:itemIconTint="#8c000000"        app:itemTextColor="#e6000000"        app:menu="@menu/navigation_menu" /></android.support.v4.widget.DrawerLayout>