Fix NewConversationActivity toolbar/overflow dynamic theming

Fixes #4624
Closes #4626

res/layout/contact_selection_activity.xml

@@ -11,7 +11,7 @@
             android:layout_width="match_parent"
             android:minHeight="?attr/actionBarSize"
             android:background="?attr/colorPrimary"
-            android:theme="@style/TextSecure.LightActionBar" />
+            android:theme="?attr/actionBarStyle" />
 
         <fragment android:id="@+id/contact_selection_list_fragment"
                   android:layout_width="match_parent"

res/values/styles.xml

@@ -31,7 +31,6 @@
         <item name="android:icon">@drawable/actionbar_icon_holo_dark</item>
         <item name="icon">@drawable/actionbar_icon_holo_dark</item>
         <item name="background">@color/gray95</item>
-        <item name="android:background">@color/gray95</item>
         <item name="logo">@drawable/actionbar_icon_holo_dark</item>
         <item name="android:popupTheme">@style/ThemeOverlay.AppCompat.Dark</item>
         <item name="popupTheme">@style/ThemeOverlay.AppCompat.Dark</item>