Two Android Auto regressions reported from the car.
1. The on/off equalizer action disappeared from the playback screen.
That was self-inflicted: commit cacd3ec removed it on the theory that a
custom action in `controls` aborts `AudioService.setState` and kills the
media notification. Reading the plugin source refutes it. setState
(AudioService.java:513-520) SPLITS the list -- a control carrying a
customAction goes to `customActions` (PlaybackStateCompat, i.e. the car),
everything else becomes a NotificationCompat.Action in `nativeActions`
(the phone notification). The two never mix. And the throw the theory
depended on cannot happen here: ic_auto_eq_on/ic_auto_eq_off both exist
under res/drawable, and the labels are non-empty in all 13 locales.
The notification outage was already fixed by abc6b47 (transient idle on
a source change, which setState turns into a full stop() at :557).
The action is back, with both state-aware icons. The real invariant --
a custom action's icon must resolve and its label must be non-empty --
is now a test that reads res/drawable and fails on a missing file,
instead of a comment claiming custom actions are forbidden outright.
2. The Ecualizador folder never listed the user's saved presets.
itemsEcualizadorAuto iterated PresetEcualizador.presets, so only the six
factory presets appeared -- the user's own were unreachable from the
car, the surface where a preset picker matters most. They now arrive
through a registered read function (same seam as stations and local
music, re-read per browse so a preset saved on the phone shows up
without an app restart).
presetsEcualizadorAuto is the single source of truth for the ordered
universe, used to BUILD the items and to RESOLVE a tap, so the folder
cannot show an item that resolution then refuses -- which is what the
factory-only default in seleccionarPresetEqPorMediaId would have caused.
A custom preset whose name collides with a factory one is dropped: the
media id is the raw name, so it could only ever resolve to the factory
entry, and an item that applies a preset other than the one it names is
worse than an absent one.
Tests: 1108 -> 1120.
On-device feedback showed the equalizer's preset-cycling custom action
looked dead: many head units render custom actions icon-first, and a
monochrome icon cannot legibly encode "which of six presets" the way a
browsable list's text rows can.
This adds an "Ecualizador" folder to the car's browse tree, listing
"Desactivar" first, then the six factory presets by name, with the
currently-active one marked. Selecting a preset routes through the same
playFromMediaId seam every other browse-tree leaf already uses; picking
a preset while the equalizer is off turns it on and applies that preset.
Supersedes the earlier "no equalizer folder" rule (commit 2403da3),
which predated this feedback -- see decision auto/ecualizador-diseno.
The preset-cycling custom action still coexists with the folder in this
commit; it is removed in the next one.