add indexing and clean the cache after enableing flat rate

Author: glo74170

app/code/Magento/SalesRule/Test/Mftf/Test/StorefrontCategoryRulesShouldApplyToGroupedProductWithInvisibleIndividualProductTest.xml

@@ -19,6 +19,8 @@
         </annotations>
         <before>
             <magentoCLI command="config:set {{EnableFlatRateConfigData.path}} {{EnableFlatRateConfigData.value}}" stepKey="enableFlatRate"/>
+            <magentoCLI command="indexer:reindex" stepKey="reindex"/>
+            <magentoCLI command="cache:flush" stepKey="flushCache"/>
             <createData entity="ApiCategory" stepKey="createCategoryOne"/>
             <createData entity="ApiSimpleProduct" stepKey="createFirstSimpleProduct">
                 <field key ="price">100</field>