Select the default clock if current clock id was not found

Bug: 295371293
Test: Manually tested invalid clock ids
Change-Id: I98d96bf72cbe09895b644a5a53f86499bf74bfab

packages/SystemUI/customization/src/com/android/systemui/shared/clocks/ClockRegistry.kt

@@ -409,6 +409,18 @@ open class ClockRegistry(
             scope.launch(bgDispatcher) { mutateSetting { it.copy(seedColor = value) } }
         }
 
+    // Returns currentClockId if clock is connected, otherwise DEFAULT_CLOCK_ID. Since this
+    // is dependent on which clocks are connected, it may change when a clock is installed or
+    // removed from the device (unlike currentClockId).
+    // TODO: Merge w/ CurrentClockId when we convert to a flow. We shouldn't need both behaviors.
+    val activeClockId: String
+        get() {
+            if (!availableClocks.containsKey(currentClockId)) {
+                return DEFAULT_CLOCK_ID
+            }
+            return currentClockId
+        }
+
     init {
         // Register default clock designs
         for (clock in defaultClockProvider.getClocks()) {

packages/SystemUI/tests/src/com/android/systemui/shared/clocks/ClockRegistryTest.kt

@@ -226,6 +226,25 @@ class ClockRegistryTest : SysuiTestCase() {
         assertEquals(mockClock, clock)
     }
 
+    @Test
+    fun activeClockId_changeAfterPluginConnected() {
+        val plugin1 = FakeClockPlugin()
+            .addClock("clock_1", "clock 1")
+            .addClock("clock_2", "clock 2")
+
+        val plugin2 = FakeClockPlugin()
+            .addClock("clock_3", "clock 3", { mockClock })
+            .addClock("clock_4", "clock 4")
+
+        registry.applySettings(ClockSettings("clock_3", null))
+
+        pluginListener.onPluginLoaded(plugin1, mockContext, mockPluginLifecycle)
+        assertEquals(DEFAULT_CLOCK_ID, registry.activeClockId)
+
+        pluginListener.onPluginLoaded(plugin2, mockContext, mockPluginLifecycle)
+        assertEquals("clock_3", registry.activeClockId)
+    }
+
     @Test
     fun createDefaultClock_pluginDisconnected() {
         val plugin1 = FakeClockPlugin()