Migrate all AlertDialogs to AndroidX version

This CL only changed AlertDialog imports.
So, reviewer can review it easily.

Change-Id: I097bc44394195b14287f4f920c570ac8653f356a
Fixes: 111413092
Test: This CL can't pass Robo test.

src/com/android/settings/fuelgauge/batterytip/tips/BatteryTip.java

@@ -16,7 +16,6 @@
 
 package com.android.settings.fuelgauge.batterytip.tips;
 
-import android.content.ContentResolver;
 import android.content.Context;
 import android.os.Parcel;
 import android.os.Parcelable;