Fix request role dialog UI not dismissing.

This change fixes the request role dialog UI so that it can be
dismissed correctly, by overriding DialogFragment.onDismiss() which
should be used instead of setOnDismissListener(). It also fixes the
theme so that there is not title panel under the dialog.

Bug: 110557011
Test: manual
Change-Id: I015c4eb3a2be577863f46b9962b16661aae81f30