Fix screenshot preview border in RTL

The constraints were pulling the border "in" from the preview edge
instead of extending "out" around it, in RTL. This change makes it
show up correctly in both LTR/RTL layouts.

Bug: 190629016
Fix: 190629016
Test: visual verification
Change-Id: I89e88479f3a268a73da444c55b54db6cfe8f2781
diff --git a/packages/SystemUI/res/layout/global_screenshot_static.xml b/packages/SystemUI/res/layout/global_screenshot_static.xml
index 60dbaf9..4eb4740 100644
--- a/packages/SystemUI/res/layout/global_screenshot_static.xml
+++ b/packages/SystemUI/res/layout/global_screenshot_static.xml
@@ -71,7 +71,7 @@
         android:background="@drawable/screenshot_border"
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintBottom_toBottomOf="parent"
-        app:layout_constraintEnd_toStartOf="@+id/screenshot_preview_end"
+        app:layout_constraintEnd_toEndOf="@+id/screenshot_preview_end"
         app:layout_constraintTop_toTopOf="@+id/screenshot_preview_top"/>
     <androidx.constraintlayout.widget.Barrier
         android:id="@+id/screenshot_preview_end"
@@ -91,8 +91,7 @@
         android:id="@+id/global_screenshot_preview"
         android:visibility="invisible"
         android:layout_width="@dimen/global_screenshot_x_scale"
-        android:layout_marginStart="4dp"
-        android:layout_marginBottom="4dp"
+        android:layout_margin="4dp"
         android:layout_height="wrap_content"
         android:layout_gravity="center"
         android:elevation="@dimen/screenshot_preview_elevation"
@@ -101,7 +100,9 @@
         android:background="@drawable/screenshot_preview_background"
         android:adjustViewBounds="true"
         app:layout_constraintBottom_toBottomOf="@+id/global_screenshot_preview_border"
-        app:layout_constraintStart_toStartOf="@+id/global_screenshot_preview_border">
+        app:layout_constraintStart_toStartOf="@+id/global_screenshot_preview_border"
+        app:layout_constraintEnd_toEndOf="@+id/global_screenshot_preview_border"
+        app:layout_constraintTop_toTopOf="@+id/global_screenshot_preview_border">
     </ImageView>
     <FrameLayout
         android:id="@+id/global_screenshot_dismiss_button"