Adds a home method to device classes. (#95103)

dev/devicelab/lib/framework/devices.dart

@@ -124,6 +124,9 @@ abstract class Device {
   /// Send the device to sleep mode.
   Future<void> sendToSleep();
 
+  /// Emulates pressing the home button.
+  Future<void> home();
+
   /// Emulates pressing the power button, toggling the device's on/off state.
   Future<void> togglePower();
 
@@ -470,6 +473,12 @@ class AndroidDevice extends Device {
       await togglePower();
   }
 
+  /// Sends `KEYCODE_HOME` (3), which causes the device to go to the home screen.
+  @override
+  Future<void> home() async {
+    await shellExec('input', const <String>['keyevent', '3']);
+  }
+
   /// Sends `KEYCODE_POWER` (26), which causes the device to toggle its mode
   /// between awake and asleep.
   @override
@@ -895,6 +904,9 @@ class IosDevice extends Device {
   @override
   Future<void> sendToSleep() async {}
 
+  @override
+  Future<void> home() async {}
+
   @override
   Future<void> togglePower() async {}
 
@@ -945,6 +957,9 @@ class FuchsiaDevice extends Device {
   @override
   Future<void> sendToSleep() async {}
 
+  @override
+  Future<void> home() async {}
+
   @override
   Future<void> togglePower() async {}
 
@@ -1011,6 +1026,9 @@ class FakeDevice extends Device {
   @override
   Future<void> sendToSleep() async {}
 
+  @override
+  Future<void> home() async {}
+
   @override
   Future<void> togglePower() async {}
 

dev/devicelab/lib/framework/framework.dart

@@ -144,6 +144,10 @@ class _TaskRunner {
       }
 
       final Device? device = await _getWorkingDeviceIfAvailable();
+
+      // Some tests assume the phone is in home
+      await device?.home();
+
       late TaskResult result;
       IOSink? sink;
       try {