Android ext.app.id may benefit from A: prefix

[maxgolov]

This is related to this gray area of Common Schema:
https://github.com/microsoft/common-schema/issues/114

Based on legacy docs for Common Schema 2.1, it appears that A: is the valid prefix that is telling the pipeline to treat the Application Identifier as one of the "App catalog identifiers". For Android that literally means "Package name, no version".

[maxgolov]

Martin Harriman (@larvacea) - if it works for Office apps (not sure what Office is expecting in their flows), appears we should consider adding the A: prefix.

[larvacea]

As far as I know, we do not use any of these fields in Office, so I see no problem with adding A: to this string.

[maxgolov]

I'm gonna work with Jan Smrcina (@jsmrcina) to get these prefixes documented in Common Schema repo. Seems like adding A: prefix is gonna align the implementation with not-very-well documented spec.. Old Aria SDK never followed that spec, now we're trying to create clarity on this.

I believe Edge-MMX is not blocked on this - Edge may easily populate the field with their own preferred value using semantic context "SetAppId" API.