Revert xml rewriting now that it's fixed in the server

[bootstraponline]

• c352e68
• Moved xpath into boostrap java appium#3428

[bootstraponline]

Also revert instance counting as that's done server side.

• 9c4672b

[KazuCocoa]

I just checked _print_source $driver.driver.page_source equals to source.
So, I'll remove _fix_android_native_source.