How to center elements in an Android LinearLayout (horizontally)

I was just working on centering some components in an Android LinearLayout and came upon this helpful advice:

android:gravity takes care of its children,
android:layout_gravity takes care of itself

So, in my case, where I wanted to center two buttons horizontally in a LinearLayout, I used android:gravity="center".

In total, all of my code for this particular layout looks like this:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
                android:layout_width="fill_parent"
                android:layout_height="fill_parent"
                style="@style/AppTheme">

    <GridView xmlns:android="http://schemas.android.com/apk/res/android"
          android:id="@+id/imagesGridView"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:columnWidth="120dp"
          android:numColumns="auto_fit"
          android:stretchMode="columnWidth"
          android:clickable="true"
          android:fadeScrollbars="true">
    </GridView>

    <android.support.v7.widget.Toolbar
        android:id="@+id/imagesGridToolbar"
        android:minHeight="@dimen/abc_action_bar_default_height_material"
        android:background="#e9111111"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        xmlns:android="http://schemas.android.com/apk/res/android">

        <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
                      android:layout_width="match_parent"
                      android:layout_height="match_parent"
                      android:orientation="horizontal"
                      android:gravity="center">

            <Button
                android:id="@+id/cancelDeleteProcessButton"
                android:text="Cancel"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:background="#c0c0c0"
                android:layout_alignBottom="@+id/imagesGridView"
                android:layout_marginRight="32dp"/>
    
            <Button
                android:id="@+id/deleteImagesButton"
                android:text="Delete"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:background="#c0c0c0"
                android:layout_alignBottom="@+id/imagesGridView"
                android:layout_toRightOf="@+id/cancelButton"
                android:layout_toEndOf="@+id/cancelButton"/>
        
        </LinearLayout>

    </android.support.v7.widget.Toolbar>

</RelativeLayout>

I highlighted the gravity piece of that code, and also highlighted the layout_marginRight specification, which provides some separation between my two buttons.

In summary, if you needed to see how to center components in an Android LinearLayout, I hope this was helpful.