Remove unused getDisplayDensity

Change-Id: I4c63f4f8c0b0d8596e6b2db9839af059961157a8
diff --git a/tests/tapl/com/android/launcher3/tapl/LauncherInstrumentation.java b/tests/tapl/com/android/launcher3/tapl/LauncherInstrumentation.java
index 65208ce..93bf9af 100644
--- a/tests/tapl/com/android/launcher3/tapl/LauncherInstrumentation.java
+++ b/tests/tapl/com/android/launcher3/tapl/LauncherInstrumentation.java
@@ -845,10 +845,6 @@
         mDevice.waitForIdle();
     }
 
-    float getDisplayDensity() {
-        return mInstrumentation.getTargetContext().getResources().getDisplayMetrics().density;
-    }
-
     int getTouchSlop() {
         return ViewConfiguration.get(getContext()).getScaledTouchSlop();
     }