add pressed state to playback buttons

vlc-android/res/drawable/ic_backward.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<selector xmlns:android="http://schemas.android.com/apk/res/android">
+    <item android:drawable="@drawable/ic_backward_normal" android:state_focused="true" android:state_pressed="false"/>
+    <item android:drawable="@drawable/ic_backward_glow" android:state_focused="true" android:state_pressed="true"/>
+    <item android:drawable="@drawable/ic_backward_glow" android:state_focused="false" android:state_pressed="true"/>
+    <item android:drawable="@drawable/ic_backward_normal"/>
+</selector>
\ No newline at end of file

vlc-android/res/drawable/ic_forward.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<selector xmlns:android="http://schemas.android.com/apk/res/android">
+    <item android:drawable="@drawable/ic_forward_normal" android:state_focused="true" android:state_pressed="false"/>
+    <item android:drawable="@drawable/ic_forward_glow" android:state_focused="true" android:state_pressed="true"/>
+    <item android:drawable="@drawable/ic_forward_glow" android:state_focused="false" android:state_pressed="true"/>
+    <item android:drawable="@drawable/ic_forward_normal"/>
+</selector>
\ No newline at end of file

vlc-android/res/drawable/ic_pause.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<selector xmlns:android="http://schemas.android.com/apk/res/android">
+    <item android:drawable="@drawable/ic_pause_normal" android:state_focused="true" android:state_pressed="false"/>
+    <item android:drawable="@drawable/ic_pause_glow" android:state_focused="true" android:state_pressed="true"/>
+    <item android:drawable="@drawable/ic_pause_glow" android:state_focused="false" android:state_pressed="true"/>
+    <item android:drawable="@drawable/ic_pause_normal"/>
+</selector>
\ No newline at end of file

vlc-android/res/drawable/ic_play.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<selector xmlns:android="http://schemas.android.com/apk/res/android">
+    <item android:drawable="@drawable/ic_play_normal" android:state_focused="true" android:state_pressed="false"/>
+    <item android:drawable="@drawable/ic_play_glow" android:state_focused="true" android:state_pressed="true"/>
+    <item android:drawable="@drawable/ic_play_glow" android:state_focused="false" android:state_pressed="true"/>
+    <item android:drawable="@drawable/ic_play_normal"/>
+</selector>
\ No newline at end of file

vlc-android/res/drawable/ic_stop.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<selector xmlns:android="http://schemas.android.com/apk/res/android">
+    <item android:drawable="@drawable/ic_stop_normal" android:state_focused="true" android:state_pressed="false"/>
+    <item android:drawable="@drawable/ic_stop_glow" android:state_focused="true" android:state_pressed="true"/>
+    <item android:drawable="@drawable/ic_stop_glow" android:state_focused="false" android:state_pressed="true"/>
+    <item android:drawable="@drawable/ic_stop_normal"/>
+</selector>
\ No newline at end of file