[java] don't suggest "implements" for type parameter (IDEA-353386)

GitOrigin-RevId: fec190f372d53eb9311a54dc01e511ef432b0ee4

java/java-impl/src/com/intellij/codeInsight/completion/JavaKeywordCompletion.java

@@ -1066,7 +1066,7 @@ public class JavaKeywordCompletion {
           }
         }
       }
-      if (!psiClass.isInterface()) {
+      if (!psiClass.isInterface() && !(psiClass instanceof PsiTypeParameter)) {
         addKeyword(new OverridableSpace(createKeyword(PsiKeyword.IMPLEMENTS), TailTypes.humbleSpaceBeforeWordType()));
       }
     }

java/java-tests/testData/codeInsight/completion/keywords/extends11.java

@@ -14,5 +14,5 @@
  * limitations under the License.
  */
 class A{
- void <T extends String, V e<caret>>foo(){}
+ void <T extends String, V <caret>>foo(){}
 }