Fix layout

app/src/main/res/layout/activity_group.xml

@@ -15,7 +15,7 @@
     You should have received a copy of the GNU General Public License along with Mastalab; if not,
     see <http://www.gnu.org/licenses>.
 -->
-<android.support.v4.widget.DrawerLayout
+<androidx.drawerlayout.widget.DrawerLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
@@ -25,24 +25,24 @@
     android:fitsSystemWindows="true"
     >
 
-    <android.support.design.widget.CoordinatorLayout
+    <androidx.coordinatorlayout.widget.CoordinatorLayout
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         tools:context="fr.gouv.etalab.mastodon.activities.GroupActivity">
 
-        <android.support.design.widget.AppBarLayout
+        <com.google.android.material.appbar.AppBarLayout
             android:id="@+id/appBar"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             >
-            <android.support.v7.widget.Toolbar
+            <androidx.appcompat.widget.Toolbar
                 android:id="@+id/toolbar"
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
                 android:background="?attr/colorPrimary"
                 app:layout_scrollFlags="scroll|enterAlways"
                 app:popupTheme="?attr/popupOverlay"/>
-        </android.support.design.widget.AppBarLayout>
+        </com.google.android.material.appbar.AppBarLayout>
         <RelativeLayout
             android:paddingLeft="@dimen/fab_margin"
             android:paddingRight="@dimen/fab_margin"
@@ -107,5 +107,5 @@
                     android:indeterminate="true" />
             </RelativeLayout>
         </RelativeLayout>
-    </android.support.design.widget.CoordinatorLayout>
-</android.support.v4.widget.DrawerLayout>
+    </androidx.coordinatorlayout.widget.CoordinatorLayout>
+</androidx.drawerlayout.widget.DrawerLayout>

app/src/main/res/values/strings.xml

@@ -1138,6 +1138,7 @@
     <string name="toot_per_day">%s statuses per day</string>
     <string name="date_range">Date range</string>
     <string name="action_groups">Groups</string>
+    <string name="no_messages">No groups!</string>
     <plurals name="number_of_vote">
         <item quantity="one">%d vote</item>
         <item quantity="other">%d votes</item>