Setting stable layout flags on the launcher, so that the instets do not
change for launcher when going in/out of another app

Bug: 27600678
Change-Id: Ic873faba99c539025769d911bc7b0a4fed629cd7
(cherry picked from commit 784f9c39962721511f19bd3ef929abd7e91fa411)
diff --git a/src/com/android/launcher3/Launcher.java b/src/com/android/launcher3/Launcher.java
index d1adc51..0dc7925 100644
--- a/src/com/android/launcher3/Launcher.java
+++ b/src/com/android/launcher3/Launcher.java
@@ -1384,8 +1384,9 @@
         mWorkspace.setPageSwitchListener(this);
         mPageIndicators = mDragLayer.findViewById(R.id.page_indicator);
 
-        mLauncherView.setSystemUiVisibility(
-                View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION);
+        mLauncherView.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
+                | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
+                | View.SYSTEM_UI_FLAG_LAYOUT_STABLE);
         mWorkspaceBackgroundDrawable = getResources().getDrawable(R.drawable.workspace_bg);
 
         // Setup the drag layer