Tweak contact selection layout

Fixes #6588

// FREEBIE

res/layout/contact_selection_list_fragment.xml

@@ -13,6 +13,8 @@
             android:id="@+id/recycler_view"
             android:layout_width="match_parent"
             android:layout_height="match_parent"
+            android:paddingTop="4dp"
+            android:clipToPadding="false"
             android:scrollbars="vertical" />
 
         <TextView android:id="@android:id/empty"

res/layout/contact_selection_list_item.xml

@@ -3,15 +3,16 @@
 <org.thoughtcrime.securesms.contacts.ContactSelectionListItem
         xmlns:android="http://schemas.android.com/apk/res/android"
         xmlns:tools="http://schemas.android.com/tools"
-        xmlns:app="http://schemas.android.com/apk/res-auto"
         android:layout_width="match_parent"
-        android:layout_height="?android:attr/listPreferredItemHeight"
+        android:layout_height="60dp"
         android:orientation="horizontal"
         android:gravity="center_vertical"
         android:focusable="true"
         android:background="@drawable/conversation_item_background"
         android:paddingLeft="48dp"
-        android:paddingRight="20dp">
+        android:paddingStart="48dp"
+        android:paddingRight="24dp"
+        android:paddingEnd="24dp">
 
     <org.thoughtcrime.securesms.components.AvatarImageView
             android:id="@+id/contact_photo_image"
@@ -20,13 +21,15 @@
             android:foreground="@drawable/contact_photo_background"
             android:cropToPadding="true"
             tools:src="@color/blue_600"
-            android:layout_marginRight="10dp"
-            android:layout_marginEnd="10dp"
             android:contentDescription="@string/SingleContactSelectionActivity_contact_photo" />
 
     <LinearLayout android:layout_width="0dp"
                   android:layout_height="wrap_content"
                   android:layout_weight="1"
+                  android:layout_marginLeft="16dp"
+                  android:layout_marginStart="16dp"
+                  android:paddingRight="16dp"
+                  android:paddingEnd="16dp"
                   android:orientation="vertical">
 
         <org.thoughtcrime.securesms.components.emoji.EmojiTextView

res/layout/contact_selection_recyclerview_header.xml

@@ -2,7 +2,7 @@
 <TextView xmlns:android="http://schemas.android.com/apk/res/android"
           xmlns:tools="http://schemas.android.com/tools"
           android:layout_width="48dp"
-          android:layout_height="?android:attr/listPreferredItemHeight"
+          android:layout_height="60dp"
           android:gravity="center"
           android:textColor="#666"
           android:textSize="22sp"