When I attempt to view an RTT transcript of a call in the dialer that ships with Graphene, I get this crash:
D AndroidRuntime: Shutting down VM
E AndroidRuntime: FATAL EXCEPTION: main
E AndroidRuntime: Process: com.android.dialer, PID: 9455
E AndroidRuntime: java.lang.RuntimeException: Unable to start activity ComponentInfo{com.android.dialer/com.android.dialer.rtt.RttTranscriptActivity}: java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity.
E AndroidRuntime: at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:4061)
E AndroidRuntime: at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:4248)
E AndroidRuntime: at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:112)
After a very brief look, it seems like a theme is never set on the RttTranscriptActivity. Perhaps the fix as simple as setting the theme on that activity to Dialer.ThemeBase.ActionBar?