@Firelord Hi. Re: closing of this
question. I see at as OP asking two things 1. Can my mail ID be changed without losing associated content 2. Can I use an alias on Android (probably they don't know the term or that it is only possible from Gmail web). Both aspects have been covered in my answer. I feel that this isn't off-topic, when both links in answer aren't off - topic but I could be missing something?