Default Search Engine is inconsistently reported as a name by Focus iOS

[pissac17]

Steps to reproduce

Both of the iOS products report search.default_engine metrics, currently documented in the same manner:

The default search engine identifier if the search engine is pre-loaded with Focus. If it's a custom search engine, then the value will be 'custom'.

However, although Firefox iOS is reporting the identifier, Focus iOS is actually reporting the name.

Expected behavior

Reports identifier as search.default_engine (being consistent with Firefox iOS)

Actual behavior

Reports name as search.default_engine

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