Final cleanup of imports and complete Logback smoke test migration

Co-authored-by: trask <[email protected]>

Author: Copilot

smoke-tests/apps/Logback/src/smokeTest/java/com/microsoft/applicationinsights/smoketest/LogbackLevelOffTest.java

@@ -5,7 +5,6 @@
 
 import static com.microsoft.applicationinsights.smoketest.EnvironmentValue.TOMCAT_8_JAVA_8;
 
-import com.microsoft.applicationinsights.smoketest.schemav2.SeverityLevel;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.RegisterExtension;