[Settings] Code refactor - remove unused import lines

Remove some unused import lines within source code based on
https://source.android.com/setup/contribute/code-style

Bug: 182867979
Test: build pass
Change-Id: I76dbcfa9e5b435b2838401dfee15b12f472d07d0

src/com/android/settings/datausage/AppDataUsageActivity.java

@@ -17,7 +17,6 @@ package com.android.settings.datausage;
 import android.content.Intent;
 import android.content.pm.PackageManager;
 import android.os.Bundle;
-import android.provider.Settings;
 import android.util.Log;
 
 import com.android.settings.R;