Allow One-handed gesture when densityDpi > 600

This logic was aim to prevent tablet device enable One-handed gesture
so added displayInfo.densityDpi < DisplayMetrics.DENSITY_600 before.

However, it seems this densityDpi=600 does not able to represent to
tablet device, instead we already have system property
"ro.support_one_handed_mode" which provides feasibility to config false
on tablet project, as the reason we can safe to remove this condition.

Bug: 203936659
Test: adb shell wm density 600 , and observe OHM gesture is available
Test: atest WMShellUnitTests
Change-Id: Ic7ae10e8a47d26b9bb39ab80e22d591d74f89ae5
diff --git a/quickstep/src/com/android/quickstep/RecentsAnimationDeviceState.java b/quickstep/src/com/android/quickstep/RecentsAnimationDeviceState.java
index e2441ed..73d1424 100644
--- a/quickstep/src/com/android/quickstep/RecentsAnimationDeviceState.java
+++ b/quickstep/src/com/android/quickstep/RecentsAnimationDeviceState.java
@@ -59,7 +59,6 @@
 import android.os.UserManager;
 import android.provider.Settings;
 import android.text.TextUtils;
-import android.util.DisplayMetrics;
 import android.view.MotionEvent;
 import android.view.Surface;
 
@@ -581,8 +580,7 @@
             final Info displayInfo = mDisplayController.getInfo();
             return (mRotationTouchHelper.touchInOneHandedModeRegion(ev)
                 && displayInfo.rotation != Surface.ROTATION_90
-                && displayInfo.rotation != Surface.ROTATION_270
-                && displayInfo.densityDpi < DisplayMetrics.DENSITY_600);
+                && displayInfo.rotation != Surface.ROTATION_270);
         }
         return false;
     }