Not using pressHome to start Launcher when tests are running in-proc

This is a risky business, as we can be broken by platform changes like:

b/118891218

Note that TAPL itself still uses pressing Home button.

Change-Id: I55772622fac5f19f6c9f19716a185bbfdbf602a9
diff --git a/tests/src/com/android/launcher3/ui/TaplTestsLauncher3.java b/tests/src/com/android/launcher3/ui/TaplTestsLauncher3.java
index 33cb5be..6f2f280 100644
--- a/tests/src/com/android/launcher3/ui/TaplTestsLauncher3.java
+++ b/tests/src/com/android/launcher3/ui/TaplTestsLauncher3.java
@@ -110,7 +110,11 @@
 
     public static void initialize(AbstractLauncherUiTest test) throws Exception {
         test.clearLauncherData();
-        test.mDevice.pressHome();
+        if (TestHelpers.isInLauncherProcess()) {
+            test.mActivityMonitor.returnToHome();
+        } else {
+            test.mDevice.pressHome();
+        }
         test.waitForLauncherCondition("Launcher didn't start", launcher -> launcher != null);
         test.waitForState("Launcher internal state didn't switch to Home", LauncherState.NORMAL);
         test.waitForResumed("Launcher internal state is still Background");