[JENKINS-16005] Use system temp directory for CommandInstaller scripts

AbstractCommandInstaller.performInstallation() was calling
createTextTempFile() with the default inThisDirectory=true,
causing it to try creating temp script files in the tool's
installation directory (e.g., /usr). This fails when Jenkins
doesn't have write access to that directory.

Changed to use createTextTempFile(..., false) to create temp
files in the system temp directory (java.io.tmpdir) instead.

Author: meetgoti07

core/src/main/java/hudson/tools/AbstractCommandInstaller.java

@@ -72,8 +72,9 @@ public String getToolHome() {
     @Override
     public FilePath performInstallation(ToolInstallation tool, Node node, TaskListener log) throws IOException, InterruptedException {
         FilePath dir = preferredLocation(tool, node);
+        dir.mkdirs();
         // TODO support Unix scripts with interpreter line (see Shell.buildCommandLine)
-        FilePath script = dir.createTextTempFile("hudson", getCommandFileExtension(), command);
+        FilePath script = dir.createTextTempFile("hudson", getCommandFileExtension(), command, false);
         try {
             String[] cmd = getCommandCall(script);
             int r = node.createLauncher(log).launch().cmds(cmd).stdout(log).pwd(dir).join();