Rename iteration variable name in PersistenceProviderUnitTests for readability

[devholic22]

Rename iteration variable name in PersistenceProviderUnitTests for readability

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In PersistenceProviderUnitTests toResourcePaths method, use iface in interfacesToImplement.

but in my opinion, targetInterface is better than iface for readability. (iface not means direct this variable is a unit of interfacesToImplement.)

In my guess, interface word is already used in java default words. (type name) so written in iface.

could you consider this suggestion?

(The two check boxes at the bottom do not seem to correspond to simple word changes, so I did not check them.)