[java] renames AppMain class to avoid clashes with an older version on the class path

(follow-up to 0c840ce2)

native/breakgen/AppMain.c

@@ -17,6 +17,6 @@
 #include <jni.h>
 #include <windows.h>
 
-JNIEXPORT void JNICALL Java_com_intellij_rt_execution_application_AppMain_triggerControlBreak(JNIEnv *env, jclass clazz) {
+JNIEXPORT void JNICALL Java_com_intellij_rt_execution_application_AppMainV2_triggerControlBreak(JNIEnv *env, jclass clazz) {
   GenerateConsoleCtrlEvent(CTRL_BREAK_EVENT, 0);
 }