Unsuppress USI low battery notifications when new stylus used.

This handles an edge case where a stylus with a different
vendor/product ID is used after a previous stylus has received a
low battery notification, and that notification has been dismissed.
Unsuppressing the notification means that if the new stylus's
battery is also low, a new notification will be sent.

Note that this means if a stylus has the same vendor/product ID
as the previous one, there is no way to differentiate them.

Bug: 262689155
Test: atest StylusUsiPowerStartableTest
Change-Id: Ia8a661a131e241216ecf9aaff89e36cb40860f91

packages/SystemUI/src/com/android/systemui/stylus/StylusUsiPowerStartable.kt

@@ -39,6 +39,17 @@ constructor(
     private val featureFlags: FeatureFlags,
 ) : CoreStartable, StylusManager.StylusCallback, StylusManager.StylusBatteryCallback {
 
+    override fun onStylusAdded(deviceId: Int) {
+        // On some devices, the addition of a new internal stylus indicates the use of a
+        // USI stylus with a different vendor/product ID. We would therefore like to reset
+        // the battery notification suppression, in case the user has dismissed a low battery
+        // notification of the previous stylus.
+        val device = inputManager.getInputDevice(deviceId) ?: return
+        if (!device.isExternal) {
+            stylusUsiPowerUi.updateSuppression(false)
+        }
+    }
+
     override fun onStylusBluetoothConnected(deviceId: Int, btAddress: String) {
         stylusUsiPowerUi.refresh()
     }

packages/SystemUI/tests/src/com/android/systemui/stylus/StylusUsiPowerStartableTest.kt

@@ -91,6 +91,20 @@ class StylusUsiPowerStartableTest : SysuiTestCase() {
         verify(stylusUsiPowerUi, times(1)).init()
     }
 
+    @Test
+    fun onStylusAdded_internal_updatesNotificationSuppression() {
+        startable.onStylusAdded(STYLUS_DEVICE_ID)
+
+        verify(stylusUsiPowerUi, times(1)).updateSuppression(false)
+    }
+
+    @Test
+    fun onStylusAdded_external_noop() {
+        startable.onStylusAdded(EXTERNAL_DEVICE_ID)
+
+        verifyZeroInteractions(stylusUsiPowerUi)
+    }
+
     @Test
     fun onStylusBluetoothConnected_refreshesNotification() {
         startable.onStylusBluetoothConnected(STYLUS_DEVICE_ID, "ANY")