Revert "Update sysui flags on swipe, skip task backgrounds on opaque apps"

This reverts commit 5dd46d51ed.

Reason for revert: Temporary revert until ag/4040557 goes in

Change-Id: Iab2c747a99e1fb1cc5a91787dbf185df77f791b4

src/com/android/launcher3/BaseActivity.java

@@ -16,7 +16,6 @@
 
 package com.android.launcher3;
 
-import static com.android.launcher3.util.SystemUiController.UI_STATE_OVERVIEW;
 import static java.lang.annotation.RetentionPolicy.SOURCE;
 
 import android.app.Activity;
@@ -154,12 +153,6 @@ public abstract class BaseActivity extends Activity {
     protected void onPause() {
         mActivityFlags &= ~ACTIVITY_STATE_RESUMED;
         super.onPause();
-
-        // Reset the overridden sysui flags used for the task-swipe launch animation, we do this
-        // here instead of at the end of the animation because the start of the new activity does
-        // not happen immediately, which would cause us to reset to launcher's sysui flags and then
-        // back to the new app (causing a flash)
-        getSystemUiController().updateUiState(UI_STATE_OVERVIEW, 0);
     }
 
     public boolean isStarted() {