Fixed logic for isWildcard function (#1171)

## Description
<!-- Provide a brief summary of the changes made and the issue they aim
to address.-->

## Testing
<!-- Describe how the changes have been tested-->

## Additional Notes to the Reviewer
<!-- Share any additional context or insights that may help the reviewer
understand the changes better. This could include challenges faced,
limitations, or compromises made during the development process.
Also, mention any areas of the code that you would like the reviewer to
focus on specifically. -->

Author: msrathore-db

NEXT_CHANGELOG.md

@@ -11,6 +11,7 @@
 
 - [PECOBLR-1131] Fix incorrect refetching of expired CloudFetch links when using Thrift protocol.
 - Fixed logging to respect params when the driver is shaded.
+- Fixed `isWildcard` to return true only when the value is `*`
 
 ---
 *Note: When making changes, please add your change under the appropriate section

src/main/java/com/databricks/jdbc/common/util/WildcardUtil.java

@@ -32,7 +32,7 @@ public static boolean isNullOrWildcard(String s) {
    * @return true if the input string is wildcard
    */
   public static boolean isWildcard(String s) {
-    return s != null && s.contains(ASTERISK);
+    return s != null && s.equals(ASTERISK);
   }
 
   public static String jdbcPatternToHive(String pattern) {

src/test/java/com/databricks/jdbc/common/util/WildcardUtilTest.java

@@ -42,7 +42,8 @@ public void testJDBCToHiveConversion(
 
   @Test
   public void testIsWildcard() {
-    assertTrue(wildcardUtil.isWildcard("*Test*"));
+    assertTrue(wildcardUtil.isWildcard("*"));
+    assertFalse(wildcardUtil.isWildcard("*Test*"));
     assertFalse(wildcardUtil.isWildcard("Test"));
     assertFalse(wildcardUtil.isWildcard(null));
   }