The service handles three different types of `Intents`. Custom command and media
command Intents created by the library and media button event Intents from other
sources.
Media commands from the library as well as from external sources have the action
set to `android.intent.action.MEDIA_BUTTON`. If the data URI is set and can be
used to identify a session then it is a library Intent. If the Intent is coming
from an external KeyEvent, the service implementation is asked which session to use
by calling `onGetSession(controllerInfo)` with the controller info being an
anonymous legacy controller info.
Intents representing a custom command are always coming from the library and hence
always have a data URI.
Issue: androidx/media#82
PiperOrigin-RevId: 453932972
Refactors the DefaultMediaNotificationProvider by separating the
selection of actions and building the notification with it.
The custom commands of the custom layout of the session are turned
into notification actions and when received from the notification
converted back to custom session commands that are sent to the
session.
PiperOrigin-RevId: 450404350
Define MediaNotification.Provider so that apps can customize
notification UX. Move MediaNotificationManager's functionality
around notifications on DefaultMediaNotificationProvider
PiperOrigin-RevId: 428024699
Where this introduced an inconsistency (e.g. assigning to something
called `windowIndex`), I generally renamed the transitive closure of
identifiers to maintain consistency (meaning this change is quite
large). The exception is code that interacts with Timeline and Window
directly, where sometimes I kept the 'window' nomenclature.
#minor-release
PiperOrigin-RevId: 407040052
