fix hardcoded strings

src/main/res/layout/activity_list_item_header.xml

@@ -10,7 +10,7 @@
         android:textSize="20sp"
         android:layout_marginLeft="10dp"
         android:layout_marginTop="10dp"
-        android:text="Header"
+        android:text="@string/placeholder_filename"
 
         />
 

src/main/res/layout/folder_sync_item_header.xml

@@ -35,7 +35,7 @@
         android:layout_toLeftOf="@+id/buttonBar"
         android:ellipsize="middle"
         android:gravity="start|center_vertical"
-        android:text="Header Text"
+        android:text="@string/placeholder_filename"
         android:textColor="?android:textColorPrimary"
         android:textStyle="bold"/>
 

src/main/res/layout/loading_dialog.xml

@@ -38,6 +38,6 @@
         android:layout_height="wrap_content"
         android:layout_gravity="center_vertical"
         android:layout_marginLeft="@dimen/standard_margin"
-        android:text="TextView" />
+        android:text="@string/common_loading" />
 
 </LinearLayout>

src/main/res/layout/share_file_layout.xml

@@ -122,7 +122,7 @@
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
                 android:layout_gravity="center_horizontal"
-                android:contentDescription="shareAddUserButton"
+                android:contentDescription="@string/share_add_user_or_group"
                 android:text="@string/share_add_user_or_group"
                 android:theme="@style/Button.Primary"/>
 
@@ -330,7 +330,7 @@
                     android:layout_width="match_parent"
                     android:layout_height="wrap_content"
                     android:layout_gravity="center_horizontal"
-                    android:contentDescription="shareGetLinkButton"
+                    android:contentDescription="@string/share_get_public_link_button"
                     android:text="@string/share_get_public_link_button"
                     android:theme="@style/Button.Primary"/>