test: add active_call filter coverage to searchEventsMaximumParamsTest

[Copilot]

The v3.7.0 schema sync (PR #45) adds a new active_call filter to searchEvents, but searchEventsMaximumParamsTest doesn't exercise it. This extends the "maximum params" test so the new parameter is covered end-to-end.

Changes

• Input value: add final Boolean ACTIVE_CALL = true;
• Expected query params: assert active_call is serialized via expectedQueryParams.put("active_call", ...), which also feeds the total param-count check
• API call: pass .setActiveCall(ACTIVE_CALL) into the searchEvents(...) invocation

final Boolean ACTIVE_CALL = true;
expectedQueryParams.put("active_call", String.valueOf(ACTIVE_CALL));

api.searchEvents(
    new FingerprintApi.SearchEventsOptionalParams()
        // ...existing params...
        .setSource(SOURCE)
        .setActiveCall(ACTIVE_CALL));

Note: this branch is stacked on PR #45's feat/open-api-v3.7.0 (where setActiveCall/active_call are introduced); it should be retargeted to that branch rather than main for review.