[FLINK-20651] Remove checkstyle checks that don't work/are not needed…

… with google-java-format

tools/maven/checkstyle.xml

@@ -31,10 +31,6 @@ This file is based on the checkstyle file of Apache Beam.
 
 <module name="Checker">
 
-	<!--<module name="FileTabCharacter">-->
-	<!--&lt;!&ndash; Checks that there are no tab characters in the file. &ndash;&gt;-->
-	<!--</module>-->
-
 	<module name="NewlineAtEndOfFile">
 		<!-- windows can use \r\n vs \n, so enforce the most used one ie UNIx style -->
 		<property name="lineSeparator" value="lf"/>
@@ -97,13 +93,6 @@ This file is based on the checkstyle file of Apache Beam.
 
 		-->
 
-		<module name="RegexpSinglelineJava">
-			<property name="format" value="^\t* +\t*\S"/>
-			<property name="message"
-					  value="Line has leading space characters; indentation should be performed with tabs only."/>
-			<property name="ignoreComments" value="true"/>
-		</module>
-
 		<!-- Prohibit T.getT() methods for standard boxed types -->
 		<module name="Regexp">
 			<property name="format" value="Boolean\.getBoolean"/>
@@ -418,32 +407,6 @@ This file is based on the checkstyle file of Apache Beam.
 		<!--value="^(package .*;\s*)|(import .*;\s*)|( *\* .*https?://.*)$"/>-->
 		<!--</module>-->
 
-		<module name="LeftCurly">
-			<!-- Checks for placement of the left curly brace ('{'). -->
-			<property name="severity" value="error"/>
-		</module>
-
-		<!--<module name="RightCurly">-->
-		<!--&lt;!&ndash; Checks right curlies on CATCH, ELSE, and TRY blocks are on-->
-		<!--the same line. e.g., the following example is fine:-->
-		<!--<pre>-->
-		<!--if {-->
-		<!--...-->
-		<!--} else-->
-		<!--</pre>-->
-		<!--&ndash;&gt;-->
-		<!--&lt;!&ndash; This next example is not fine:-->
-		<!--<pre>-->
-		<!--if {-->
-		<!--...-->
-		<!--}-->
-		<!--else-->
-		<!--</pre>-->
-		<!--&ndash;&gt;-->
-		<!--<property name="option" value="same"/>-->
-		<!--<property name="severity" value="error"/>-->
-		<!--</module>-->
-
 		<!-- Checks for braces around if and else blocks -->
 		<module name="NeedBraces">
 			<property name="severity" value="error"/>