[refactor] Make Regex more simple and clear (#6141)

1. Remove Redundant character escape ‘\\}’ and ‘\\:’
2. Replace ‘{0,1}’ to ‘?’

fe/fe-core/src/main/java/org/apache/doris/common/ConfigBase.java

@@ -120,7 +120,7 @@ public class ConfigBase {
     // the "CONFIG_VALUE" should be replaced be env variable CONFIG_VALUE
     private void replacedByEnv(Properties props) throws Exception {
         // pattern to match string like "{CONFIG_VALUE}"
-        Pattern pattern = Pattern.compile("\\$\\{([^\\}]*)\\}");
+        Pattern pattern = Pattern.compile("\\$\\{([^}]*)\\}");
         for (String key : props.stringPropertyNames()) {
             String value = props.getProperty(key);
             Matcher m = pattern.matcher(value);

fe/fe-core/src/main/java/org/apache/doris/common/util/TimeUtils.java

@@ -73,7 +73,7 @@ public class TimeUtils {
                     + "((0?[1-9])|([1-2][0-9])|(30)))|(0?2[\\-\\/\\s]?((0?[1-9])|(1[0-9])|(2[0-8]))))))"
                     + "(\\s(((0?[0-9])|([1][0-9])|([2][0-3]))\\:([0-5]?[0-9])((\\s)|(\\:([0-5]?[0-9])))))?$");
     
-    private static final Pattern TIMEZONE_OFFSET_FORMAT_REG = Pattern.compile("^[+-]{0,1}\\d{1,2}\\:\\d{2}$");
+    private static final Pattern TIMEZONE_OFFSET_FORMAT_REG = Pattern.compile("^[+-]?\\d{1,2}:\\d{2}$");
 
     public static Date MIN_DATE = null;
     public static Date MAX_DATE = null;