Support tracking in H5P activities

This issue should be tested both in Android and iOS. You should check that the behaviour of the app is consistent with the Moodle web behaviour. Some things to take into account: There is a course in master site called "H5P reports" that contains several H5P activities. For students, the usual behaviour is to open the activity, play it and check the attempts you already did. You can also prefetch the activity, or leave an attempt unfinished and check that no tracking is generated (the same should happen in web). For teachers, you can play the package but no tracking is generated (you should see a warning). If an H5P activity has tracking disabled you should see the same warning for students too. Teachers cannot see the attempts of students in the app, it's a feature that will be added later (on 4.0). When opening an H5P activity that hasn't been played/downloaded before, if the h5p file is lower than 20MB (WiFi) or 2MB (3G) the package will be played automatically, otherwise you'll have to click a button. The "course presentation" h5p attached to this issue is bigger than 2MB so it can be used to test this. Once an H5P package has been downloaded or played before it should always start automatically when opened. Downloading the H5P file (play it) will not mark the whole activity as downloaded, because downloading the activity also means downloading the data about the attempts. The activity can be played in offline, and the app should save the data to be synchronized later. Configure H5P activities to have different grading methods (highest attempt, average, ...) and check that it works as expected. As admin, go to "Site administration > Mobile app > Mobile features" and disable "View H5P content offline". In the app, check that you see a warning and the package plays fine (only in online).