Ensure the account is syncable flag is set

On some versions of Android, this flag is not set by default.
Unfortunately, that means we need to request yet another permission.

Signed-off-by: Greg Meiste <greg.meiste@gmail.com>
Hide "Phone LED" setting on devices without intrusive LED. Closes #128

This is the same method used by the Android Settings app to determine
whether to show the "Pulse notification light" option. However, since
this app isn't a system app, the resource ID needs to be looked up to
get access to the Android internal resources.

Signed-off-by: Greg Meiste <greg.meiste@gmail.com>