Fix maven plugin smoke test

- Do not use default encoding to avoid warnings in logs
- Update 'Downloading'/'Downloaded' filters to new maven version

libraries/tools/kotlin-maven-plugin/src/it/simple/pom.xml

@@ -9,6 +9,10 @@
     <artifactId>test-project</artifactId>
     <version>1.0</version>
 
+    <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+
     <dependencies>
         <dependency>
             <groupId>junit</groupId>

libraries/tools/kotlin-maven-plugin/src/it/simple/verify.groovy

@@ -23,8 +23,8 @@ State state = new File(basedir, "build.log").readLines().collect { it.replaceAll
     def m = pattern.matcher(line)
     if (m.find()) {
         acc.currentPlugin = m.group(1)
-    } else if (line.startsWith("[INFO] Downloaded:") ||
-               line.startsWith("[INFO] Downloading:") ||
+    } else if (line.startsWith("[INFO] Downloaded") ||
+               line.startsWith("[INFO] Downloading") ||
                line.startsWith("Downloaded:") ||
                line.startsWith("Downloading:") ||
                line.startsWith("[INFO] PERF:")) {