Expose heads up, (1/2):

Thanks to CyanogenMod:
https://github.com/CyanogenMod/android_frameworks_base/commit/6c65b35e061409b15ccccacf86d58dadbf655e26
https://github.com/CyanogenMod/android_frameworks_base/commit/6551a47c998c6892260dc45e9db7f1c66832cd33
https://github.com/CyanogenMod/android_frameworks_base/commit/cb85a9086a32906d4b65f19a7609870ce0d9836e
https://github.com/CyanogenMod/android_frameworks_base/commit/802d3e7d2a6c0d7c29fa4f4a652615836bb6a3e5

Included:
- Enable/disable heads up
- Do not disturb
- Blacklist