[GR-13445] [GR-16616] Adopt the new property for pre-initialization.

PullRequest: graalpython/554

Author: eregon

graalpython/com.oracle.graal.python/.checkstyle_checks.xml

@@ -34,6 +34,7 @@
       <property name="format" value="^[_a-zA-Z][_a-zA-Z0-9]*$"/>
     </module>
     <module name="RedundantImport"/>
+    <module name="UnusedImports"/>
     <module name="LineLength">
       <property name="max" value="300"/>
     </module>

mx.graalpython/native-image.properties

@@ -3,7 +3,7 @@
 
 Requires = language:regex language:llvm
 
-JavaArgs = -Xmx4G -Dpolyglot.engine.PreinitializeContexts=python
+JavaArgs = -Xmx4G -Dpolyglot.image-build-time.PreinitializeContexts=python
 
 Args = -H:MaxRuntimeCompileMethods=7000 \
        -H:+AddAllCharsets \