Reduce lint warning

Signed-off-by: Joris Bodin <joris.bodin@infomaniak.com>

src/main/res/drawable/shimmer_background.xml

@@ -1,5 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="rectangle">
-    <solid android:color="@color/grey_200"/>
-    <corners android:radius="@dimen/file_icon_rounded_corner_radius"/>
-</shape>

src/main/res/layout/grid_sync_item.xml

@@ -18,7 +18,6 @@
   License along with this program.  If not, see <http://www.gnu.org/licenses/>.
 -->
 <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
-    xmlns:app="http://schemas.android.com/apk/res-auto"
     android:id="@+id/grid_item_container"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
@@ -30,6 +29,7 @@
         android:id="@+id/thumbnail"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
+        android:contentDescription="@null"
         android:scaleType="centerCrop"
         android:src="@drawable/folder" />
 

src/main/res/layout/list_item.xml

@@ -54,7 +54,6 @@
                 android:id="@+id/thumbnail"
                 android:layout_width="@dimen/file_icon_size"
                 android:layout_height="@dimen/file_icon_size"
-                android:layout_centerInParent="true"
                 android:layout_marginStart="@dimen/standard_half_margin"
                 android:contentDescription="@null"
                 android:src="@drawable/folder"/>

src/main/res/values/dims.xml

@@ -119,7 +119,6 @@
     <dimen name="grid_item_shared_icon_layout_top_margin">24dp</dimen>
     <dimen name="grid_item_local_file_indicator_layout_width">16dp</dimen>
     <dimen name="grid_item_local_file_indicator_layout_height">16dp</dimen>
-    <dimen name="grid_sync_item_layout_next_text_size">22sp</dimen>
     <dimen name="grid_sync_item_layout_counter_text_size">22sp</dimen>
     <dimen name="list_item_favorite_action_layout_width">16dp</dimen>
     <dimen name="list_item_favorite_action_layout_height">16dp</dimen>

src/main/res/values/strings.xml

@@ -567,7 +567,6 @@
     <string name="synced_folders_preferences">Preferences for auto uploading</string>
     <string name="synced_folders_new_info">Instant uploading has been revamped completely. Re-configure your auto upload from within the main menu.\n\nEnjoy the new and extended auto uploading.</string>
     <string name="synced_folders_preferences_folder_path">For %1$s</string>
-    <string name="synced_folders_plus" translatable="false">+</string>
     <plurals name="items_selected_count">
         <!--
              As a developer, you should always supply "one" and "other"