Don't reformat javadoc comments with extra *

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=274236131

core/src/main/java/com/google/googlejavaformat/java/JavaInput.java

@@ -154,7 +154,9 @@ public boolean isSlashStarComment() {
 
     @Override
     public boolean isJavadocComment() {
-      return text.startsWith("/**") && text.length() > 4;
+      // comments like `/***` are also javadoc, but their formatting probably won't be improved
+      // by the javadoc formatter
+      return text.startsWith("/**") && text.charAt("/**".length()) != '*' && text.length() > 4;
     }
 
     @Override

core/src/test/java/com/google/googlejavaformat/java/JavadocFormattingTest.java

@@ -50,7 +50,7 @@ public void empty() {
       "class Test {}",
     };
     String[] expected = {
-      "/** */", "class Test {}",
+      "/***/", "class Test {}",
     };
     doFormatTest(input, expected);
   }

core/src/test/resources/com/google/googlejavaformat/java/testdata/B142553964.input

@@ -0,0 +1,8 @@
+/*************************************************************************************************************************************************************
+ * Copyright
+ *
+ * Some
+ *
+ * Company
+ *************************************************************************************************************************************************************/
+class T {}

core/src/test/resources/com/google/googlejavaformat/java/testdata/B142553964.output

@@ -0,0 +1,8 @@
+/*************************************************************************************************************************************************************
+ * Copyright
+ *
+ * Some
+ *
+ * Company
+ *************************************************************************************************************************************************************/
+class T {}