Review J2N read-only collections performance

[paulirwin]

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Task description

Split from #928:

Originally posted by @NightOwl888:

Each of the read only collections in J2N has a "Default" mode, which kicks in if the type being passed in is a J2N collection, where the rules of structural equality are defined. If it is a BCL or 3rd party collection, it will use "Aggressive" mode, which tries to patch the collection externally with the same behavior. But "Aggressive" mode is very costly in terms of performance.

... we should only use "Aggressive" mode if we are dealing with a user-supplied collection that we have no control over. However, if we have control over the concrete collection type that is used (or default), we should always ensure that a J2N collection is used for each of these calls so we don't downgrade to "Aggressive" mode. So, it would be a good idea to review to make sure we didn't swap to any BCL collections where it could matter.

Review usage of J2N read-only collections to ensure they use the Default mode.