session-android/res/layout/webrtc_incoming_call_overlay.xml

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

    <org.thoughtcrime.securesms.components.multiwaveview.MultiWaveView
            android:id="@+id/incomingCallWidget"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="true"
            android:layout_marginBottom="-46dp"
            android:background="@android:color/black"
            android:visibility="gone"
            />

    <TextView android:id="@+id/redphone_banner"
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:layout_alignTop="@id/incomingCallWidget"
              android:gravity="center"
              android:paddingTop="8dp"
              android:paddingBottom="8dp"
              android:textAppearance="?android:attr/textAppearanceLarge"
              android:textColor="#FFFFFF"
              android:textAllCaps="true"
              android:background="@color/textsecure_primary"
              android:text="@string/redphone_call_controls__signal_call"/>

</RelativeLayout>