overlay: Change max rotator sessions to 4 and log level

Change max rotator sessions to 4, since we could support upto
those many.

Change error log to warning log on reaching beyond max rotator
sessions, since its not really an error, but flagging it as one
raises false positives in testing filters.

Change-Id: Ib06a00bce57dfa9dbda3f2e6874a31ce1a155463
2 files changed