Don't duplicate "jetbrains-" in desktop entry filename (RIDER-13712)

platform/build-scripts/groovy/org/jetbrains/intellij/build/impl/LinuxDistributionBuilder.groovy

@@ -264,6 +264,6 @@ class LinuxDistributionBuilder extends OsSpecificDistributionBuilder {
       .replace(' ', '-')
       .replace("intellij-idea", "idea").replace("android-studio", "studio")
       .replace("-community-edition", "-ce").replace("-ultimate-edition", "").replace("-professional-edition", "")
-    "jetbrains-" + name
+    name.startsWith("jetbrains-") ? name : "jetbrains-" + name
   }
 }
\ No newline at end of file

platform/platform-impl/src/com/intellij/ui/AppUIUtil.java

@@ -171,7 +171,7 @@ public class AppUIUtil {
       .replace(' ', '-')
       .replace("intellij-idea", "idea").replace("android-studio", "studio")  // backward compatibility
       .replace("-community-edition", "-ce").replace("-ultimate-edition", "").replace("-professional-edition", "");
-    String wmClass = VENDOR_PREFIX + name;
+    String wmClass = name.startsWith(VENDOR_PREFIX) ? name : VENDOR_PREFIX + name;
     if (DEBUG_MODE) wmClass += "-debug";
     return wmClass;
   }