oniro-image-base-tests: add polkit to distro features

Some oniro integration tests use udisks2 which requires polkit
feature.

Signed-off-by: Le Van Quach <levan.quach@kalpa.it>

meta-oniro-core/recipes-core/images/oniro-image-base-tests.bb

@@ -6,7 +6,7 @@ require recipes-core/images/oniro-image-base.bb
 
 SUMMARY = "Oniro Project image including the base OS software stack and tests"
 
-DISTRO_FEATURES:append = " ptest"
+DISTRO_FEATURES:append = " ptest polkit"
 
 IMAGE_INSTALL:append = "\
     packagegroup-oniro-tests \