activity_main.xml

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/container"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.test.MainActivity"
    tools:ignore="MergeRootFrame">
    
	<Button
	    android:id="@+id/button1"
	    android:layout_width="wrap_content"
	    android:layout_height="wrap_content"
	    android:text="\u003C"
	    android:padding="0dp"
	    android:textAppearance="?android:attr/textAppearanceLargeInverse"
	    android:minHeight="0dp"
	    android:minWidth="0dp" />

</FrameLayout>

MainActivity.java

package com.example.test;

import android.app.Activity;
import android.os.Bundle;

public class MainActivity extends Activity {

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
	}
}