[android] Change light theme background color closer to white

briar-android/src/main/res/layout/activity_threaded_conversation.xml

@@ -13,7 +13,8 @@
 	<FrameLayout
 		android:layout_width="match_parent"
 		android:layout_height="0dp"
-		android:layout_weight="1">
+		android:layout_weight="1"
+		android:background="@color/thread_item_background">
 
 		<org.briarproject.briar.android.view.BriarRecyclerView
 			android:id="@+id/list"

briar-android/src/main/res/values-night/color.xml

@@ -23,7 +23,6 @@
 	<color name="briar_button_text_disabled">#23cccccc</color>
 
 	<color name="thread_indicator">@color/briar_blue</color>
-	<color name="thread_item_background">@color/window_background</color>
 	<color name="thread_item_highlight">@color/briar_black</color>
 
 	<color name="divider">@color/briar_black</color>

briar-android/src/main/res/values/color.xml

@@ -23,7 +23,7 @@
 	<color name="briar_primary_dark">@color/briar_blue_very_dark</color>
 	<color name="briar_accent">@color/briar_blue</color>
 
-	<color name="window_background">#E3EBEF</color>
+	<color name="window_background">#EBEBEB</color>
 	<color name="card_background">@color/cardview_light_background</color>
 	<color name="item_background_highlight">#DCDCDC</color>
 	<color name="briar_warning_background">@color/briar_red</color>
@@ -59,7 +59,7 @@
 	<color name="briar_button_text_disabled">#28000000</color>
 
 	<color name="thread_indicator">@color/m_grey_500</color>
-	<color name="thread_item_background">@color/m_blue_grey_50</color>
+	<color name="thread_item_background">@color/window_background</color>
 	<color name="thread_item_highlight">@color/briar_white</color>
 
 	<color name="divider">#c1c1c1</color>