Swipe Buttons on bottom of the screen

Question

I just implemented a nice ScreenSlide Activity that swipe between pages both with the user's swipe gesture and with the Next and Previous buttons. I did so by attempting to reproduce the behavior of this tutorial.

My problem is that the Next and Previous buttons are always shown in the Action Bar, while in the animations of the tutorial they are shown at the bottom of the screen when in Portrait mode, and in the action bar only when in landscape mode.

This is what I want to obtain:

and this is what I get:

my ScreenSlideActivity:

http://pastie.org/private/zetuetehtvpa1gotn11ua

ScreenSlidePageFragment:

http://pastie.org/private/eqzt9dw1rc586rqapais2w

activity_screen_slide.xml:

http://pastie.org/private/vur5e7tz4ldo0fpz47ymbg

frag_info_screen_slide_page.xml:

http://pastie.org/private/qzmpeavktum4tc5jsg45ww

my Gradle:

apply plugin: 'com.android.application'

android {
    compileSdkVersion 21
    buildToolsVersion "21.1.2"

    defaultConfig {
        applicationId "madapps.bicitourbo"
        minSdkVersion 14
        targetSdkVersion 21
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
    sourceSets { main { assets.srcDirs = ['src/main/assets', 'src/main/assets/images'] } }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])

    compile 'com.android.support:appcompat-v7:22.2.0'

    //Play Services
    compile 'com.google.android.gms:play-services-maps:7.5.0'
    compile 'com.google.android.gms:play-services-location:7.5.0'

    compile 'com.android.support:design:22.2.0'
    compile 'com.google.code.gson:gson:2.3.1'
    compile 'com.googlecode.objectify:objectify:5.1.5'

    compile 'de.hdodenhof:circleimageview:1.2.1'
    compile 'com.android.support:recyclerview-v7:21.0.3'

}

EDIT

After a great deal of searching I found out that the slide buttons will only go down when the buttons would extend FragmentActivity and android:theme=@android:style/Theme.Holo.Light.DarkActionBar is set in the manifest file, whereas apparently there isn't another way to obtain the same result while using the newest AppCompatActivity, requiring you using Theme.AppCompat.Light themes instead.

Any help with this issue would be appreciated