fix shimmer background marge for grid mode

Signed-off-by: Abdourahamane Boinaidi <abdourahamane.boinaidi@infomaniak.com>

src/main/res/layout/grid_image.xml

@@ -43,7 +43,8 @@
                 android:layout_width="match_parent"
                 android:layout_height="match_parent"
                 android:background="@color/grey_200"
-                android:padding="@dimen/standard_eigth_padding"
+                android:layout_margin="@dimen/standard_eigth_padding"
+                android:scaleType="centerCrop"
                 android:visibility="gone" />
 
             <ImageView