Fix VVM playback control buttons don’t support TALKBACK

Change-Id: Ie1f81a4eaacc85bcab6fd3b32f081e83a4c36467
Signed-off-by: HUANG Menghuai <menghuai.huang@orange.com>
diff --git a/res/layout/playback_layout.xml b/res/layout/playback_layout.xml
index 01ed2e9..640daed 100644
--- a/res/layout/playback_layout.xml
+++ b/res/layout/playback_layout.xml
@@ -41,6 +41,7 @@
                 android:layout_height="match_parent"
                 android:background="?android:attr/selectableItemBackground"
                 android:src="@drawable/ic_hold_pause"
+                android:contentDescription="@string/description_playback_start_stop"
             />
         </LinearLayout>
         <LinearLayout
@@ -55,6 +56,7 @@
                 android:layout_height="match_parent"
                 android:background="?android:attr/selectableItemBackground"
                 android:src="@drawable/ic_speakerphone_on"
+                android:contentDescription="@string/description_playback_speakerphone"
             />
         </LinearLayout>
     </LinearLayout>
@@ -87,6 +89,7 @@
             android:layout_marginStart="64dip"
             android:max="0"
             android:layout_centerVertical="true"
+            android:contentDescription="@string/description_playback_seek"
         />
         <TextView
             android:id="@+id/playback_position_text"
@@ -117,6 +120,7 @@
             android:paddingTop="29dip"
             android:layout_alignParentStart="true"
             android:layout_centerVertical="true"
+            android:contentDescription="@string/description_rate_decrease"
         />
         <ImageButton
             android:id="@+id/rate_increase_button"
@@ -128,6 +132,7 @@
             android:paddingTop="29dip"
             android:layout_alignParentEnd="true"
             android:layout_centerVertical="true"
+            android:contentDescription="@string/description_rate_increase"
         />
         <View
             android:layout_width="match_parent"