Fix bad background color in dark theme

vector/src/main/java/im/vector/riotx/features/home/room/detail/RoomDetailFragment.kt

@@ -20,7 +20,6 @@ import android.annotation.SuppressLint
 import android.app.Activity.RESULT_OK
 import android.content.Context
 import android.content.Intent
-import android.graphics.Color
 import android.graphics.drawable.ColorDrawable
 import android.net.Uri
 import android.os.Bundle
@@ -105,6 +104,7 @@ import im.vector.riotx.features.media.VideoMediaViewerActivity
 import im.vector.riotx.features.notifications.NotificationDrawerManager
 import im.vector.riotx.features.reactions.EmojiReactionPickerActivity
 import im.vector.riotx.features.settings.PreferencesManager
+import im.vector.riotx.features.themes.ThemeUtils
 import kotlinx.android.parcel.Parcelize
 import kotlinx.android.synthetic.main.fragment_room_detail.*
 import kotlinx.android.synthetic.main.merge_composer_layout.view.*
@@ -350,7 +350,7 @@ class RoomDetailFragment :
 
     private fun setupComposer() {
         val elevation = 6f
-        val backgroundDrawable = ColorDrawable(Color.WHITE)
+        val backgroundDrawable = ColorDrawable(ThemeUtils.getColor(requireContext(), R.attr.riotx_background))
         Autocomplete.on<Command>(composerLayout.composerEditText)
                 .with(commandAutocompletePolicy)
                 .with(autocompleteCommandPresenter)

vector/src/main/res/layout/item_autocomplete_user.xml

@@ -4,6 +4,7 @@
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="wrap_content"
     android:layout_height="wrap_content"
+    android:background="?riotx_background"
     android:orientation="horizontal"
     android:padding="8dp">
 
@@ -21,6 +22,7 @@
         android:layout_marginStart="12dp"
         android:layout_marginLeft="12dp"
         android:maxLines="1"
+        android:textColor="?riotx_text_primary"
         android:textSize="12sp"
         android:textStyle="bold"
         tools:text="name" />