Fix dbprovider test failures when run on a real cluster or setMetastoreListener = true, when db/tab gets recreated their associated privileges will be deleted.

There are a couple of tests fail because they create db(table) /grant privileges, then drop/recreate db(table), when run on real clusters or setMetastoreListener = true, these privileges will be deleted. These tests are located in:

org.apache.sentry.tests.e2e.dbprovider.TestDbUriPermissions.testAlterTableLocationPrivileges
org.apache.sentry.tests.e2e.dbprovider.TestColumnEndToEnd.testBasic
org.apache.sentry.tests.e2e.dbprovider.TestDbPrivilegesAtDatabaseScope.testUseDbPrivilege
org.apache.sentry.tests.e2e.dbprovider.TestDbRuntimeMetadataRetrieval.testShowTables3
org.apache.sentry.tests.e2e.dbprovider.TestDbRuntimeMetadataRetrieval.testShowTablesExtended
org.apache.sentry.tests.e2e.dbprovider.TestDbRuntimeMetadataRetrieval.testShowTables1
org.apache.sentry.tests.e2e.dbprovider.TestDbSandboxOps.testNegativeUserDMLPrivileges
org.apache.sentry.tests.e2e.dbprovider.TestDbSandboxOps.testNegUserPrivilegesAll
org.apache.sentry.tests.e2e.dbprovider.TestDbSandboxOps.testSandboxOpt13
org.apache.sentry.tests.e2e.dbprovider.TestDbSandboxOps.testSandboxOpt10
org.apache.sentry.tests.e2e.dbprovider.TestDbUriPermissions.testLoadPrivileges