Fix Launcher drop targets for App remove / uninstall / info

- make the code aware of the layout direction
- use start drawables
- fix animation drop rect

Change-Id: I35f01b9079aef418c0a22b39e32344c7bf5a0660
diff --git a/res/layout/drop_target_bar.xml b/res/layout/drop_target_bar.xml
index 5fcddc9..ca3f554 100644
--- a/res/layout/drop_target_bar.xml
+++ b/res/layout/drop_target_bar.xml
@@ -23,7 +23,7 @@
             style="@style/DropTargetButton"
             android:id="@+id/delete_target_text"
             android:text="@string/delete_zone_label_workspace"
-            android:drawableLeft="@drawable/remove_target_selector" />
+            android:drawableStart="@drawable/remove_target_selector" />
     </FrameLayout>
     <FrameLayout
         xmlns:android="http://schemas.android.com/apk/res/android"
@@ -34,6 +34,6 @@
             style="@style/DropTargetButton"
             android:id="@+id/info_target_text"
             android:text="@string/info_target_label"
-            android:drawableLeft="@drawable/info_target_selector" />
+            android:drawableStart="@drawable/info_target_selector" />
     </FrameLayout>
 </merge>
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