Switching from mDevice.pressHome() to mLauncher.pressHome()

Using mDevice.pressHome() was a workaround for the shifted-search bug.

Change-Id: I740db2109af531c55f8ab59a42998bdc329fb72e
Tests: affected tests
diff --git a/quickstep/tests/src/com/android/quickstep/TaplTests.java b/quickstep/tests/src/com/android/quickstep/TaplTests.java
index 6a1123e..347b7ac 100644
--- a/quickstep/tests/src/com/android/quickstep/TaplTests.java
+++ b/quickstep/tests/src/com/android/quickstep/TaplTests.java
@@ -104,7 +104,7 @@
 
         clearLauncherData();
 
-        mDevice.pressHome();
+        mLauncher.pressHome();
         waitForState("Launcher internal state didn't switch to Home", LauncherState.NORMAL);
         waitForResumed("Launcher internal state is still Background");
     }
@@ -424,7 +424,7 @@
         executeOnLauncher(launcher -> assertTrue("Flinging backward didn't scroll widgets",
                 getWidgetsScroll(launcher) < flingForwardY));
 
-        mDevice.pressHome();
+        mLauncher.pressHome();
         waitForLauncherCondition("Widgets were not closed",
                 launcher -> getWidgetsView(launcher) == null);
     }
diff --git a/tests/src/com/android/launcher3/ui/AbstractLauncherUiTest.java b/tests/src/com/android/launcher3/ui/AbstractLauncherUiTest.java
index 8c03e4b..1b34598 100644
--- a/tests/src/com/android/launcher3/ui/AbstractLauncherUiTest.java
+++ b/tests/src/com/android/launcher3/ui/AbstractLauncherUiTest.java
@@ -123,7 +123,7 @@
                 public void evaluate() throws Throwable {
                     try {
                         // Create launcher activity if necessary and bring it to the front.
-                        mDevice.pressHome();
+                        mLauncher.pressHome();
                         waitForLauncherCondition("Launcher activity wasn't created",
                                 launcher -> launcher != null);
 
diff --git a/tests/src/com/android/launcher3/ui/AllAppsIconToHomeTest.java b/tests/src/com/android/launcher3/ui/AllAppsIconToHomeTest.java
index 9354862..fdf87be 100644
--- a/tests/src/com/android/launcher3/ui/AllAppsIconToHomeTest.java
+++ b/tests/src/com/android/launcher3/ui/AllAppsIconToHomeTest.java
@@ -21,14 +21,12 @@
         LauncherActivityInfo settingsApp = getSettingsApp();
 
         clearHomescreen();
-        mDevice.pressHome();
-        mDevice.waitForIdle();
 
         final String appName = settingsApp.getLabel().toString();
         // 1. Open all apps and wait for load complete.
         // 2. Drag icon to homescreen.
         // 3. Verify that the icon works on homescreen.
-        mLauncher.getWorkspace().
+        mLauncher.pressHome().
                 switchToAllApps().
                 getAppIcon(appName).
                 dragToWorkspace().